Flying Viking
Pre-takeoff checklist
I understand your points because I used to work for a company where I could pull down around 30% performance bonus. But I suspect that both of us had jobs with a lot more influence on the bottom than these hourly people have. They are well paid even though only one of them has more than a high school education. Plus, this is just a Christmas bonus. They also get other performance bonuses. This is a gift from me and my wife that they get even when the company is losing money.
It certainly changes things if this is a Christmas gift rather than their one and only annual performance bonus...as other posters above have suggested, could you give the gift in a different form, such as a gift card? It may be deemed a little impersonal if it's only a different amount on the salary statement..?