You just missed a great "fun fly" in Fremont sponsored by Bob "Top 10 at Poway" McGowan.
Monitor this thread on the Bay RC groups site for upcoming events:
Also, you can usually find at least one DLGer flying at the Alameda County Fairgrounds in Pleasanton. Sure, it's not Vallejo, but it's a great site for DLG (and TD) flying. Plus, when the thermals get blown out in the PM you're about 20 mintues from Del Valle - so bring your slopers, too.