No problems
I've entered AA lounges without a problem where my boarding pass had the AA # but I had entry via Oneworld sapphire (in my case it was AirBerlin status). They scan your boarding pass, then you show the other OW card (even the card is not necessary as long as you have the number - they can type it in). Then their system will show access for you and one guest. Just be clear on what the rules are, don't leave it up to the agent to come to a wrong conclusion.