There are a few airports where the OneWorld carrier shares an airport lounge. You can be denyed status there if not traveling on the carrier in the qualifying cabin. For example, we flew out of Naples in March on BA in coach. We are both Platinum on AA. We were denied admittance to the lounge as we were not in business. The attendant showed us a letter, stating that it was not a BA lounge, and therefore BA was free to set its own qualifying criteria to use it.