Northern California has a ton of options for wineries to visit. If you are staying in Pleasanton there are great local options like Rubino Estates or Wente in Livermore. If you want to take a 45 min - 1 hr drive you will have unlimited options in the world famous Napa Valley & Sonoma!
When we started dating Charlie would travel from the east coast to visit Jenae. It became our tradition to grab an Irish Coffee at the Buena Vista before we parted from each other. This is a top stop for us.
Home of the SF Giants and site of Jenae & Charlie's first date. Well worth a stadium tour, which you can find at the link below.