Davidthomson: If you are traveling LHR-LAX and then LAX-YYZ, then that is not a wholly North American itinerary, so the AA exception you highlight should not apply. I note you are flying LHR-LAX economy, so lounge access at LAX would only apply if you have a oneworld Emerald of Sapphire tier frequent flyer card.
Thanks oneworld4u. My main query was because both flights are on diferent tickets, not the same. So I didnt know if that still qualified as one itinerary or not. I am Sapphire, so no problem for access as far as that goes. Cheers.