My wife and I are newcomers to San Francisco and Napa Valley, so this was a nice introduction. I purchased this trip as a Christmas present to her, as a nice little weekend get-away, and I am overall pleased with the experience.
It was interesting to hear the tour guide explain the historical context behind the places we passed through, both in the city of San Francisco, and in Sonoma county. Her doing so made the long drive seem shorter than it actually was, which we appreciated. I have to mention that it was a particularly hot day in Sonoma County, and the air conditioning on the bus did not work well -- obviously this may not happen every time, but it could be a factor if you choose to do this trip during a hotter season. The photo opportunity at Golden Gate Bridge was a good touch.
I was a bit surprised and disappointed that none of the wineries we visited were on the original itinerary. The first winery, BR Cohn Winery was far and away the best winery of the day -- classic breathtaking Napa sights, and the wines were phenomenal. I would go back there a thousand more times.
The second winery was decent; I think it was called Madonna Estate Winery. The tour guide there was very charming, had a good sense of humor, and explained things in a way that everyone could understand, even if you had no advanced knowledge about wines or wine-making. It was a family owned winery, and it certainly did have a family-like vibe. Wines were a step down from the first winery, but still solid.
The third winery, Sutter Home, was honestly very disappointing. I'm not a wine expert, but Sutter Home, to me, isn't exactly an extremely elegant wine where I would go out of my way to visit the vineyard. It actually didn't really feel like a vineyard; it felt more like a wine souvenir shop. The workers there were pleasant, but not really wine enthusiasts or experts per se. My wife won a contest where she guessed the number of corks in a container, and her prize was getting 30% off of anything in the store; to me, if you win a contest, you should get something for free. I thought that was kind of lame to be quite honest.
As we drove through Sonoma County, our tour guide told us about all of the wineries we were passing, some of which sounded amazing, like Carneros Winery (which was brought in pieces from France, and resembles a French chateau). As I listened to all of this, I couldn't help but wonder why we weren't going to THOSE wineries instead. But like I said, it was a nice day overall, and I would recommend this if it is your first time in Napa and you don't really know which winery/wineries to choose. Having a pre-planned schedule is easy and convenient; all you have to do is get on the bus. It is obviously advantageous to have a bus chaperone you for the day, so you don't have to worry about having a designated driver. If you are serious about wine, go to BR Cohn and Carneros on your own. We will probably focus on those two next time, and get an airbnb nearby.