The Club is right at the top of the moving steps after security in T1. Flight's on sCO IAH/EWR will be out of T2. You can get through security to get to the club with UA boarding pass, regardless of gate/terminal. SAN is one of the top 10 airport to clear security in a reasonable amount of time >15min with priority boarding. With how nightmare that traffic is around the airport, it's easier to walk between terminals, which isn't that far. Terminal 2 has 0 *A clubs at their disposal as sCO/US are the only members in that building.