Bonuses are nice but unfortunately they are taxed at a higher rate than normal income. In the days when I used to get one, I was dismayed at the big chunk Uncle Sam would take out of the check.
A few years ago our company was giving these little token bonuses of $50 or so as a thank you or for a specific task. I received one, and the next pay I saw my check shrink by $23 or so. I found out that was the Federal tax on the little bonus!
This is a common and incorrect understand. WITHHOLDING is generally higher on bonuses but you always only owe whatever the marginal tax is when you true up in Jan-Apr. By law, federal taxes on bonuses must be withheld at 25% as most people's marginal tax rate is 25% (effective rates are generally much lower) but you'll owe April 15 whatever you actually do (0%, 10%, 12%, 22%, etc up to 37% now).