I don’t believe you can guest or pay for access but Il leave that for someone to confirm..
Apologies for the hijack, but to add a second question. It says it’s for pax arriving BA flights only, would this still apply to an AA ticket on BA metal JFK-LHR?
yes for the arrivals lounge It’s the cardholder only.
I don’t think it matters whether it’s a ba or aa ticket, so aa ticket for ba operated flight should be fine.