Really nice. I am an Excel expert and understand exactly what you did.

Suggestions:

Do the EQP lookup table for the two airlines you personally fly (AA and AS). Then, others downloading your spreadsheet can add their own lookups for the partner airlines they fly. There's no real need for a totally comprehensive lookup table. The client user would just add their own partner airline info to your template.

I usually put lookup tables in a separate "Lookup" sheet to make the main sheet neater.

Similarly, create a lookup table for the city pairs mileage. Many people flying for business tend to fly between the same city pairs most of the time. Thus, a lookup table for those city pairs would be useful. As with the EQP, I'd just fill out your own selected city pairs, and let others add their own following your template. The client user would add a new city pair to the end of the lookup list when flying to a new place. This would avoid duplicate mileage data entry and allow for a quick update.

A small quibble: You have duplicate info with the flight number and airline column both containing the airline code. You might consider swapping the columns and just putting flight numbers in the right column. It would still read "correctly": AA 123. As you might have guessed, I am really good about avoiding duplicate data entry. Not a big deal here, but when you get into Really Big Data as I am every day, it starts to add up.

Finally, I noticed your past flight dates are in green. Did you do that with conditional formatting or did you just change the fill color manually? Conditional formatting would work great here.