Interesting that last minute change in the SCL-JFK from 3 to 1.. it could be those are the paid upgrades? I honestly don't think LATAM is actually displaying bids, not because they don't want to, but because the overall IT department is way way way behind the technology available in other airlines (starting with the fact that you can't book multi-segment flights).

Regarding your experience in JFK, even better than Special Services picking you up and getting you tot he front of the line, is using Delta One's dedicated security and lounge. It’s without a doubt the best business class lounge in the United States, and I’d argue it’s one of the top few business class lounges in the world.