Here is an example...

19:45 HND/DFW 17:41

AA176, 11h 56 min, Direct
Premium Economy, 80,500 points + $44.65 USD

I try to book this on Alaska Airlines using miles and this flight does not show up.
It IS an American Airlines flight, but when using seats.aero, it gives me the option to book thru Alaskan.

I need to book thru Alaskan cause I can transfer my AMEX points to Alaskan, but not American Airlines.

I hope this makes my question clearer.