EF shows they just book into regular LA booking classes (G, O, Q, N, etc), so they would be eligible for mileage/MQD earning and MM miles (Fare basis codes for Light fares end in a 1, Standard in a 4, and Full in a 7). It looks like LA Elites still get free seat assignments, baggage, etc. on Light fares. Looks like DL Medallions should be eligible for these too as don't see any exceptions listed for LA Light fares -- https://www.delta.com/us/en/skymiles...yteam-benefits . However, I would not expect any of these benefits to extend to non-status companions which is typical when flying on partners.