I think this is in the midst of change.

I flew LAN intra-Argentina (SLA-AEP) on Dec 2, and the in-flight magazine, if I recall correctly, was talking about the very "new" LAN Colombia. It sounded as if they have just taken over an airline with a different name and renamed them. I get the impression LAN Colombia is headed for OneWorld, but whether it's there yet or when it is officially there that I'm not sure.

And meanwhile, aa.com has a history of being out of date on some stuff like this. So it may or may not be correct about the current status.