Recently, I flew with gf on Etihad from MEL to CDG, via Abu Dhabi. We weren't allowed into the Etihad lounge in Abu Dhabi because even though our flight from there to CDG was an Etihad code, it was codeshare with Air France.
Believe me when I say I was pissed and made sure everybody knew, including the travel agent that booked us that deals with high end corporate travellers.
Etihad lost a bunch of business from AU because of that.
It sounds like the travel agent’s fault for not booking the flight properly. Delta Skyclubs have the marketed and operated by rule, meaning that if you buy and get the ticket issued by Air France then you would have a flight marketed by Air France but Operated by Delta. Of course if this was on a business class ticket you’d have access to any SkyTeam lounges anyways.
That's some particular Etihad setup then? When I travel there's often codeshare involved, but as long as the ticket (and the boarding pass shows this) is from the airline I booked with, then I get lounge access (if my ticket allows it) and everything else if there's anything. Doesn't matter if the actual flight is with some other company.
Believe me when I say I was pissed and made sure everybody knew, including the travel agent that booked us that deals with high end corporate travellers.
Etihad lost a bunch of business from AU because of that.