Who is Aer Lingus affiliated with?
Aer Lingus is affiliated with British Airways, Iberia, and Vueling, which are collectively members of IAG. All share Avios as their points currency, though each airline has its own Avios earning and spending options.
Though Aer Lingus isn’t part of an airline alliance, you can earn AerClub Avios when flying Aer Lingus, British Airways, and United.