In Sonoma square check out cafe le haye-fantastic resturaunt, food and staff! make a reservation! its right off the square and a great romantic spot.
vineyards to visit: hartford court, iron horse-stunning scenery, if during week try visiting miramar torres....the west dry creek area is beautiful drive particaulary if you hire a convertible.
look into the maradona inn in Healdsburg -they have a great resturaunt, its a guest house, very private and romantic. I think they are online
San Fran- check out sfgate.com for their top 100 resturaunts, highly encourage you to visit ferry building,
romantic resturaunts-if you want a once in lifetime dinner, chec out fleur de lys
others-cafe jacqueline if you like nothing but souffles. again romantic.
suggest you take the 280 south when you get through the city on your way to carmel..Big Sur is highly recommened.
for all resturaunts make resevers soon! as it is getting hard to get tables at the best places..