Must be ticketed on DL regardless do marketed or operating carrier.

"Any time you purchase and fly on a Delta flight (flight number with a “DL” airline code), you’ll receive MQDs for the ticket’s base fare and carrier-imposed surcharges, but not for taxes or fees. You’ll also earn MQDs for Economy Comfort™ and Preferred Seating purchases ticketed through Delta. Flight spend on Group 1, Group 2 and Group 3 partner airlines that are ticketed through a Delta channel (the ticket number will begin with “006”) count toward MQDs as well, but certain specialty tickets such as bulk, consolidator or vacation packages do not. For more about what counts and what doesn’t, see the FAQs."