More on tunnels in the San Francisco area:
The San Francisco-Oakland Bay Bridge is made up of two sections. One section goes from San Francisco to Yerba Buena Island. The other section, the eastern section, goes from that small island to Oakland. The two sections are connected by a tunnel that goes through the island. While it's high enough to handle RVs and big trucks, there have recently been problems with chunks of concrete falling from the inside of it. You may not run into problems but expect there to be construction delays until they fix it.
By the way, the eastern section of the bridge is new. It's really beautiful any time but at night, it's spectacular. During the day, you'll see the old bridge being torn down, which is fun to watch.
Highway 24, east of San Francisco, has yet another tunnel. This is known as the Caldecott Tunnel.
There are several bores through the hillside, each handling a lane or two of traffic. Big trucks go through it, so RV heights should pose no worries. I couldn't find any propane restrictions, either, HOWEVER, the Caldecott Tunnel was the scene of a horrible fire in 1982. A gasoline tanker truck exploded in the middle of the tunnel, killing 7 people. The tunnel acted as a chimney for the smoke and flames. These kinds of tankers are no longer allowed there unless it's in the middle of the night when there's no traffic. Still, I'd make sure that your propane is OFF before you enter this tunnel.