I've never actually been in this situation before, so I'm not sure how to go about it.

I'm Aeromexico Oro, which is Skyteam Elite. I'm traveling to Mexico on Delta at the end of the month, and they just redid my ticket so that I have no legs on AM anymore. However, I now have two legs that show 2 cabin classes on Delta metal.

Will I be upgraded if I switch from my Delta number to my AM number? Who would I ask about this? Delta or AM? I'll have 3 1/2 hours in Mexico City in the lounge before these two flights happen, so would those agents in there be able to check for and issue an upgrade even if I have my Delta number attached still?

If there were still AM legs on the ticket I would have my AM number on there, but since I'm already requalled and won't hit plat, I'm going for the Delta miles.

If you're elite on DL, switch your number for upgrades. Otherwise, probably a waste unless you'll be flying DL a lot and really need to get elite on them as well. I have no knowledge of the AM FF program, but I'd guess you get bonus miles and such, which you won't if you're non-elite on DL.

I'm trying to build miles on DL for an award, not status, which is why I've got the number attached currently.

So, I *should* switch the number to the AM one for the two class flights in order to have any chance for upgrade? Who would I ask to be put on the upgrade list, and when?

I don't think DL has an upgrade agreement with Aeromexico. So I don't think it matters which number you have in there. I was speaking from the point of which program you'd earn the most miles in.