Napa is only about 45min-1.5hr from SF depending on which part of the wine country you are visiting and we usually make it a day trip. However, if you drive a bit further north, you will get to Healdsburg, Sonoma for additional (usually less crowded) group of wineries that are super fun to visit. We like to make it an overnight trip to be able to visit multiple wineries and spend more time in downtown (super cute!). Below are few of wineries to visit in Healdsburg
Lambert Bridge: Usually members only (we were referred) so relatively private but they sometimes accommodate you if you call and ask. Really good red wines, loved our host and the tasting room is super cozy. Not sure about the tasting fee but bottles are $80+. If you get a chance to visit, you will have a great time.
R.Fanelli: We saw the entrance to the winery while driving by, looked them up online and made a reservation for the next day. Cute little family owned winery focused on Cab and Cab blends. They usually only have 2-3 wines to taste (4 wines in their entire portfolio) but the host was great and will tour you around the cave. Remember tasting fee to be not much, probably around $10, we got it waived with a bottle purchase.
Lancaster Estate: Larger winery within the Foley Food and Wine family of wineries. Beautiful grounds and good big bold red wines.
Martorana: Casual spot with a picnic area for games and tasting wines. Enjoyed their Merlot!
Jordan: We ended up not being able to visit due to timing but have gotten recommendation for their food pairing. From their website the grounds look beautiful and seem to have reds, whites, and sparkling