Quick clarification: Although bonuses are usually subject to tax withholding at a rate higher than most people's actual tax rate, come April 15, the bonus will be subject to tax at the same rate as all your other ordinary income (unless the bonus pushes you into a higher bracket, which is highly unlikely).
Passing it along to someone else you think really deserves it is very generous of you. 🙂
If I were you, I'd go ahead and simply pass along the whole amount to them - but in giving that unsolicited advice I'm assuming that you aren't in a very high federal tax bracket (and unless you're a pilot, or you're married to a high income earner, how COULD you be in a high tax bracket - you work for an airline)?