You won't be able to get back the $80 you spent on BA luggage fees. BA clearly publishes that OWS and OWE are not entitled to free luggage on Basic Economy. You got lucky in BOS.

Unlike IB, where you are entitled to it. That's why the did not charge anything on your MAD-BOS sector.

As a side note, Iberia Airport Services offers ground services (check-in, ramp services, handling, etc) to many airlines, including Iberia, British Airways, Vueling, American Airlines, LEVEL, Qatar, Emirates, Norwegian, Air Europa,... at different stations.