Haven't been to any events (yet) but it sounds like fun. Do you ever hold an event in or near San Francisco? (Yes, by some standards, Sonoma could be called "near" but three-plus hours of driving (roundtrip) doesn't qualify in my book!)
I'm not sure if the usual practice is to have the event at a winery tasting room, if that's the case there are obviously a lot more possibilities up in Napa and Sonoma than in SF. Do you usually do them on a weekend? Daytime or evening? Usually when I come up that way, I like to hit 2, 3, 4 wineries and make a day of it. If it fit into that sort of day, I'd be more tempted, schedule permitting.
I'm just one guy, so I'm not trying to upset the apple cart, just wondering what I can expect. (If it doesn't work out for me, ya'll have my blessing to imbibe and enjoy without me.) ;-)