Why would it have to be narrowed down to such a level?
NATS has targets to meet, if it makes them company wide bonus. If it doesn't no bonus.
Bonuses are non-pensionable and non-consolidated. A nice little packet now might feel good, but not so clever when it comes to calculating your pension or redundancy.
We also went down this route with pay deals in the past, having lump sums tied to wishy-washy company-wide targets and it was generally agreed it was a disaster and we shouldn't go there again.
Be careful what you wish for.