And yet load factors are dropping and revenue is only increasing at a rate lower than fare inflation.

If it has been "wildly successful", there's no real need for bonuses. The volume of customers who can drop £10k on CW to the US is a thin skim, the overall volume of revenue comes from the middle spenders scaled by sheer numbers. BA also need a critical mass of motivated Avios collectors to pitch at their potential partners. So far they have Wineflyer and some theatre in London (forgive me if I've missed something) plus a rather less than enthusiastic Amex.