Hey--
Petaluma is about 45 minutes north of San Francisco. It's near the wine country, if that means anything to anyone under the age of 21. However, if I were to go, I'd check out some redwoods and the coast. (two places for beautiful flourish scenery)
The closest magic-y thing might actually be Joel Paschall's very own California Magic. On Friday and Saturday nights they have dinner and a show. You never know who will show up. You can get more info at calmagic.com. Its probably an hour an 10 minutes away from where you will be, but I used to drive an hour an a half every weekend to see it when I lived in Modesto.
Just FYI. Hope it helps.
Katie