I recently completed two flights with LATAM and Tier Points and Avios failed to post automatically. After contacting BA and completing the claim online BA said that a LATAM frequent flyer number was associated with the booking. I have never created a LATAM account, and I I made sure during check in that my BAEC number was on the booking.
Going through Flyertalk I can see this is a fairly common IT issue and I'll have to go through some bureaucracy and be asked to upload some stuff to
http://www.britishairways.com/ecsupportingdocs before getting the points. However looking through my boarding passes (which were on Apple wallet) I can't see where my BAEC number is shown. So I'm unsure how to prove my BAEC number was on the booking? Maybe I can prove I don't have a LATAM account so that they can't be credited anywhere else?