Kokanut, here is what I know. I may not have all the facts exact but in a nut shell it's what is going on.
Berryessa and the land around is owned by the government. There were a few marinas and resorts operating there and had been for many years. Problem was it was starting to become a magnet for riff raff. Trailer homes were all over, some pumping raw sewage into the lake. Drugs, weekend partyers, just not looking good in general. So, when a few years ago all the leases were up the powers that be started kicking everyone out. I for one was happy about this. Get em all out! They are now looking for some big time contractors or investers to come in and build some nice marinas, camp grounds and resorts. That would be a beautiful thing. Problem is the economy is still a bit slow so it's just not happening. Two of the marinas however were let be. I guess because they were kept up. Pleasure cove as you mentioned and Markely cove. I would suggest Markely cove. They have cabins you can rent.It is right by the dam and that is where some of the good Koke fishing is as far as I know. Later in the summer the main body of the lake is where they are. Down deep.
Berryessa is in Napa Co. and you are less than an hour drive down the hill (maybe 35 min.) to the Napa Valley. You can take Monticello road from the lake right into Napa or you can take (I think) Chiles Pope Valley Road down and end up in St. Helena on the Silverado trail.
Hope this helps. I've lived in Napa most of my life so feel free to ask me any questions.