Markus Bokisch has grown into the kind of man who doesn’t mind having his wife in his business. But it didn’t happen overnight. In fact, it wasn’t until he was steering a ’67 Volkswagen Camper through the vineyards of Spain with his wife, Liz, that he realized how they could work together.

“We drove from village to village — this is prior to GPS and mobile phones — and more often than not I would want to throw the map out the door and take a blind turn,” Bokisch says. “But Liz would be more organized and had better timing in thinking about things like finding a farmer’s market to prepare dinner. You come into conflict initially, then you begin to learn how to compromise to have the best of both worlds.”

Before that trip overseas in the early 1990s, Liz was a high school teacher and Markus worked in the wine business. But in Europe, as they met couples who owned small family vineyards, Markus and Liz decided they wanted to own a winery. Upon returning to California, they settled in the Lodi area, and Liz quit her job to help her husband develop Bokisch Vineyards, a sustainably farmed boutique winery. A decade later, Markus and Liz represent one of the many couples who believe a marital bond makes for good business.

According to the National Federation of Independent Business, about 1.2 million husband and wife teams owned small businesses nationwide in 2003. But experts expect that number to rise because of the high unemployment rate, the increase of women starting their own companies and an increase in baby-boomer couples looking to make extra bucks before retiring. The benefits are obvious: in-house support, loyalty, shared passion, more time together and, potentially, twice the revenue.

But trouble can sprout when the line between marriage and business gets blurry, says Barbara E. Thompson, a senior partner with The Discovery Group, which specializes in addressing concerns of family businesses and entrepreneurial couples.

To maintain balance, Markus and Liz have established strict boundaries. They email each other often, even when they’re in the same room, set meeting times and coordinate calendars on their BlackBerrys. They take vacations at least twice a year and always eat dinner together with their sons, ages 12 and 14.

They refuse to go to bed angry, a lesson they learned from a retired couple years ago, and try to avoid making last-minute decisions to keep any bitterness at bay.

“If we don’t agree on something, chances are we don’t agree because we’re emotionally too involved in our own view of the outcome,” Markus says. “So we try not to make a decision at the eleventh hour. We’d be better off letting it go for a year.”

Perhaps their most important rule is that all business talk ceases once the clock strikes 5 p.m.

“It’s hard sometimes, but we have to draw the line,” Liz says. “If you don’t stop, it can really take over your life.”

Thompson agrees. If couples don’t manage their time accordingly, the constant work can sap energy from the relationship, she says, and before long, a spouse may want to quit not just the business but the marriage.

“Or there’s the classic one where the couple gets divorced and continues the business together,” says John Roe, also a senior partner in The Discovery Group based in Cameron Park. “Some people find they’re better business partners than marriage partners.”

Unlike the couples they counsel, Thompson and Roe work together, but they’re not married to each other. While many couples come to them with startup dreams seeking advice, the husband-and-wife business venture isn’t always intentional.

“Many times, we work with entrepreneurial couples who ended up working together by default,” Thompson says. “One of them needs help with bookkeeping, and the spouse gets involved and lo and behold, they end up in business together without even realizing it.”

In other cases, couples work together at a company that they didn’t start. That’s the story of retired TV anchors Dave Walker and Lois Hart. They met at KOVR in 1976 and married in 1979. They anchored CNN’s first broadcast and worked together at KCRA from 1990 until their retirement in November 2008.

But Walker and Hart say they had no rules when it came to separating work and married life. It was no big deal if they wanted to “talk shop” after hours, Walker says. The couple says the fact that they get along well has always helped, but even when things in their personal life got “frosty,” Walker says they made sure to keep it professional at the workplace.

“Many married couples don’t have the benefit of a neutral territory where they both have to behave,” Hart says.

Since retiring, the couple has been traversing the globe, cruising through the Panama Canal, riding the train across the country and river rafting through the Grand Canyon. Even now, they don’t understand why so many people ask them how they managed to work and live together all those years.

“Up until World War II, the common experience was for husbands and wives to live and work together,” Walker says. “They’d work on the farm or at a store, and everybody chipped in. The notion that living and working together is unusual, I find that surprising.”