LOTS of things and we don't know which one we should go to!!!
In the Sonama/Napa area, there is Robert Mondavi Music Festival http://www.robertmondaviwinery.com/index.cfm?method=pages.showPage&PageID=6ff4e4f6-bb70-23a3-b368-e0f2012e74fd&originalMarketingURL=Visit-Us/Concerts
Not only there is great music, there is also great wine.
There are also some really awesome restaurants nearby. We find Ad Hoc to be super memorable. We went there with our clients and truly enjoyed every bit. http://www.yelp.com/biz/ad-hoc-yountville-2#hrid:2FtMJauqt1Z9DgGcEqcerw
In San Francisco, of course there is the America’s Cup Races http://www.americascup.com/en/sanfrancisco which will continue throughout the whole month of July.