Never mind the state of the cabin etc. These guys, if the cabins are filthy, have been flying filthy cabins around for 11 (ish) months waiting for that 12th month bonus.
Regardless of when the bonus system was introduced it is all relevant to what is written in the individual contract, now whether that be a fock up of AIE or Rishworth/Sigmar is besides the point, if the individual is contractually entitled to a bonus then the individual should receive a bonus, indeed a contractual entitlement.
Amen