So I DM'd AS Twitter about LATAM and asked about mileage plan credit on LATAM subsidiaries since I was booking a ticket on (formerly) TAM within Brazil. Andre on twitter said they're only partners with LAN Chile.

Interestingly, AS MP website does not distinguish between the (original) LAN Chile and other LAN branded carriers (Peru, Columbia, Argentina). I couldn't find anything about LAN Chile only. Oddly, the website was promoting Brazilian destinations (although, yes, you could fly to Brazil through Chile on LAN)

LATAM has renamed all of its subsidiaries as LATAM (Country X), so LAN Chile does not technically exist. When booking through TAM, sure enough, there was a place to add my AS MP number. The twitter agent kept insisting LAN Chile every time I asked about LATAM. Any ideas as to when/if all LATAM flights will be MP eligible?