RV park near Vacaville or Winters Caifornia

Depending on the season, Vineyard has a grape arbor and they let you pick grapes. Many interesting varieties -- champagne, cabernet, and so forth. Delicious!

Thank you all for the advice. I will make a reservation at Vineyard RV.

when I go to Giants games in SF I stay at Tradewinds in Vallejo. From the park (located along I-80), I can take the ferry from Vallejo to SF, drive, or head for the closest BARTD station.

There is a county/city park in Winters with RV hookups. Nice CG.

We've stayed at VineyardRVpark.com numerous times. We will be there again in late September, as we have good friends who live in Vacaville. Most of the park is older and rustic, with lots of trees, easy access, and good clean hookups. There is a newer section which is fully paved, but all spots are backins in that section and you give up the trees.
Enjoy

This one isn't too bad.
Between the 505 and I-80

http://vineyardrvpark.com/

You could stay closer to San Francisco'

Golden Gate Mobil and RV Park

or

Marin RV Park

Depending where your appointment is, the Larkspur Ferry is an enjoyable ride. I have stayed at the Marin RV Park several times and walked (10 minute walk) over to the Larkspur Ferry Terminal and rode the ferry to Market Street.

Wayne