Hi Tim,
We recently stayed at the San Francisco Rv Resort. If you can get a site water front you have incredible views. Not cheap!! The sites are really close together but with the view is hard to beat. Bart (like the subway) is about 3 miles north so you don't have to drive into the City with your pickup. The resort is in Pacifica.
Near Yosemite there is a small RV park in El Portal named Indian Flat Campground. Look it up on the net. Haven't stayed there for 20 years but it is really close to the park.
Hopefully other locals, like myself, will chime in with helpful hints.
If you happen to golf, there is a golf resort in Chowchilla, Ca. between the bay area and Yosemite which include a round a golf for 2 with a nights stay.
http://www.thelakesrv.com/
We happen to live in Chowchilla and store our Monty there. If you happen by give us a Email