Never heard of it ... then I looked it up and it was Sonoma County Airport Express, and I'd frequently see those buses. Two hours and fifteen minutes total travel time with stops between SFO and STS!

But then again, rental car pickup, gas, dropoff, plus GGB toll if driving southbound will add up, both in time and money.
The alte kaker price is $50.
If things don't work out, I'm not available