Social media is exploding in the wine business and a new survey illustrates just how important it has become, especially in this tough economic climate. More than 80 percent of 109 grape growers, distributors, retailers and other wine experts in the California who were questioned in a survey by the Wine Industry Financial Symposium Group and the University of California-Davis Graduate School of Management said they were using Facebook in their business, up from 46 percent in 2009.