Echoing some previous posters, I believe that this is the natural result of many years of accumulated greed by executives, be they captains of industry or public sector chiefs/QUANGOcrats.
My initial feeling was that it was indeed an utter liberty to demand a bonus for performing their regular jobs, but what may be seen as cynicism on the part of the bus drivers/train drivers etc is easy to understand. Even if they do get these £500 payments, this will be a mere 160th of the £80,000 bonuses that TfL directors stand to receive.
Elsewhere we see so-called golden parachutes for failing executives, often for as much as 5 or 6 times what the average Brit will earn in a lifetime. Meanwhile those nearer the bottom of the employment pyramid are made redundant and often offered as little as 1 weeks salary per year worked with whatever the company or organisation is.
At the risk of straying into tinfoil hat territory, I think that we are rapidly approaching a tipping point where widespread social unrest/violence will result.