I got platinum. Can someone explain to me how the benefits work(free bags, lounge access and good seats) if I fly a partner airline. Do I have to book through the aa site or do i book through the partner site (example ba) and put in my aa frequent flyer number. Which lounge do I get access to the aa or ba lounge in this example. It said I have sapphire one world status with the platinum but i do not see a sapphire number anywhere. Please explain to me how it works.