Not true ... generally, I've had to take it out at 25% federal tax, regardless of filing status. I depends on whether it is additional bonus in a regular paycheck, or truly a bonus check. If you follow the regular tax tables, you are liable to have too much taken out.
Federal FICA tax (Social Security and Medicare) will be withheld at the required 7.65% rate on all taxable supplemental wages. Federal income tax will be withheld at the IRS required flat 25% supplemental pay tax rate for bonuses, lump sum vacation pay, and other pay that is not routine (weekly/monthly) in nature.