I've heard that the Ridge is a great Winery close to the Silicon Valley. On weekends, they are open from 11 am - 4 pm. Plan to meet at Ridge at 2 pm.
We will also hit up Picchetti Winery on the way back to get another good tasting in! Look forward to seeing everyone there.
Address for Picchetti
13100 Montebello Road
Cupertino, CA 95014