Originally Posted by
aviators99
One thing I liked about the AA partnership was the ability to use the AA lounge if you were a member and were flying B6. No mention of that here, unfortunately. One place it would be useful is LGA terminal B.
I think the reasoning there was AA and B6 were fully coordinating schedules and sharing revenue. Part of that was often ceding routes to one or the other (e.g. ATL-LGA went entirely to B6 during that period). Adding AC access for their AC members when flying B6 was probably done to ensure AC members (who are often elites) didn't leave for DL if the route flipped to B6.