It seems it's even worse than the OP states. Yes, UC passengers do have access to the Star Alliance lounge, but VS has moved operations back to T2—a quick check of today's flights out of LAX confirmed this. So if you want lounge time, you have to check in at T2, walk to TBIT for the SA lounge and then back to T2 for your flight. Seems that access to the Delta Sky Club in T2 has been removed for UC passengers. The only way of mitigating the hassle would be if you're not checking baggage; then you can check-in online and go straight to TBIT when you arrive at LAX as they allow you to pass through security at any terminal. Or if you're getting dropped off by friends or family, have them wait for you while you check-in/drop bags at T2, then drive you to TBIT.