Even as the global economy has faltered in the past four years, a handful of privately owned wine companies have become active in acquiring wine operations, brands and vineyards. “The one consistent trend in the market has been the increased acquisition activity of privately held wine companies and the noticeable absence of publicly traded beverage companies,” said Mario Zepponi, whose Santa Rosa-based company has advised buyers and sellers in a number of the recent North Coast wine industry mergers and acquisitions.