Great Friday happy-hour/dinner location before Alcatraz tour?

[cherie]

In late August, my husband and I are scheduled for a Friday night Alcatraz tour starting at 6:45 p.m.

This will be the day we arrive into SF from the Midwest, and we would like to go someplace great for drinks/wine and a light meal/appetizers before the tour, say, around 4:30-ish.

Ideally, the location would be somewhat convenient to our route (the Four Seasons on Market Street to Pier 33/Alcatraz ferry).

Before we decided to take the tour that evening, we originally planned to have dinner at Bar Agricole, but that's out because they apparently do not open until 5:30 p.m.

Any suggestions??

Thanks in advance. :)