The problem with bonuses, is that they are very easy to abuse, and many corporations have incredibly rigid bonus systems that actually make it difficult to reward individual excellence.
I was just talking with a friend of mine a couple of days ago. He's a Director at a manufacturing plant, and is awesome.
He spent the last year, working 7 days a week, ten hours a day, to implement some new processes. The company is being put out to bid for sale, and his efforts doubled the price.
His efforts alone.
Doubled the price of the company.
He got a tiny raise, and all Directors get the same bonus, based on sales numbers (which weren't so good). Also, all Directors get the same percentage of equity.
I suspect that he may be seeing who else could use his talents...