Any system that incentivizes having coworker under deliver is a bad idea. There is no reason bonuses have to fall in that category and in my personal experience they never have. Where I have worked bonuses we bases on a combination of personal performance, team performance and company performance so you got a bigger bonus if your coworkers did well.
See this every day in a large Investment Bank. Bonus chasing bastards do not protect or grow the brand, they just ensure short term decisions remain the order of the day.