There is an interesting article on California's wine labelling laws in the San Francisco Chronicle today . It covers the issues and obstacles that the Napa Valley Vintners have had in dealing with new sub-appellations within the larger designated California appellations such as Napa and Sonoma. The article explains the problems that arose when a new sub-appellation was proposed for Calistoga which affected the winery, Calistoga Cellars, which buys most of its grapes from outside Napa.
Grandfathering provisions exist in California for brands that existed in 1986 or earlier but a new system is proposed including a rolling grandfathering rule and additional labelling requirements. The article canvasses the brand vs. terroir arguments well and may serve as an indicator of arguments to come in the BC wine country. Incidentally, BC's geographic content requirements are stricter than California's. Under BC's new laws, 95% of the grapes have to come from the appellation area identified on the bottle. In California, only 85% have to do so.