Flight
SFO and OAK are equidistant to Sonoma. SFO is better if you plan on flying United. OAK is better if you plan on flying Delta / Southwest. Alternatively, Charles M. Schulz-Sonoma County Airport (STS) is another option if flying in more locally. Rental cars, taxis, and Uber/Lyft are available at all airports.
Hotel
Cost: Mid Tier
Hotel
Cost: Upper-mid tier to upscale
Hotel
Cost: Upscale boutique