Originally Posted by
DMPHL
You'll have access to the Flagship Lounge in MIA (not Flagship First Dining), but won't have access at LAX, because you are not continuing your itinerary on a OW flight.
In my experience (and as I think others have reported), AA lounge access is de facto granted throughout a OW international F/J (or EXP/PPR/PLT) itinerary, including upon arrival if the lounge is physically accessible. Indeed, the typical scenario for this is arriving at the USA final destination on an AA domestic connection.