Those concerns are warranted in some cases. In Colorado, Oregon and Washington, where recreational use has been legal for several years, beer sales are down, mostly among mass-market brews. The liquor industry opposed several marijuana legalization initiatives last year, and has expressed fears for its bottom line.

The fine wine industry, however, has not panicked. Despite occasional efforts to pit wine and weed against each other, people in the wine business exude an air of mellow acceptance that the two substances can coexist in harmony.

"People are trying to say there is a threat, but I really haven't talked to any wine industry person yet who actually sees it that way," said Tina Caputo, a freelance wine and food writer, who in August will be a moderator at the first Wine & Weed Symposium. The event, a wine industry initiative, will explore possible business opportunities in California, which legalized recreational marijuana use in November.