Nor is the Centurion lounge.

However, I wonder whether the domestic to domestic connection especially could really use AEP rather than EZE. There are two BsAs airports, with EZE being international and most domestic flights using AEP.

SkyTeam ElitePlus status gives access to all SkyTeam lounges on the same day as a SkyTeam international itinerary, which would include the AR lounge on the same day (arrival or departure, but note that it's a departure lounge and there is no arrival lounge at EZE for SkyTeam) as the international flight. However, if you can't get to the door of the lounge due to the way passport control is handled at the airport, theoretical access doesn't go you any good.