Technically you need a license "inside" the bridge at Vallejo, in the waters of the Carquinez Straits. However, we've been told in the past by the wardens that no license would be required on piers through Benicia. In other words, inland of the Benicia Bridge was where they started giving tickets, at least as far as the piers. I assume (which can be dangerous) that it is still true. The piers in Pittsburg and Antioch would thus needed licenses.
Igor, Ken's correct, I've spoken to Wardens on the Martinez pier. I've only seen them question people who've said they were targeting Sturgeon and they've asked to see their tags. Met a Wildlife Officer down there a while back named Henry Twomey, he was doing just that walking the pier. I asked him if i could contact him if I ever had any questions and he gave me his direct number. Really nice guy and I've run into him a couple times now at the bait shop down there.