Hmmm, why not both? Drunken kareoke AND spa!!

I'm thinking Japantown in San Francisco has a pretty good spa and I'm sure has kareoke...or head North for wine tour (glad you have limos, don't drink and drive or hit the cyclists) and mudbaths in Calistoga or Sonoma Mission Inn in Sonoma? Great places there for you to ride afterward but I don't know if there is Drunken kareoke in Sonoma or Calistoga. You could bring your own machine.

Or book the Napa Valley wine train and have it end with a stop at a spa.