The Mallard in Albany (Berkeley) has been suggested. Evidently, it has an upstairs room and food. Here is the link: http://www.clubmallard.com/
How's this sound?
+1 to Club Mallard as long as we've got a good place to get some work done! The only catch is if it'll cost...
I'd probably be able to host 8-10 people at my house in Napa for a honing event.