I'm a little long winded here, but I have some strong feelings on this subject.
Any reputable financial advisor would tell you the same thing: the first and best investment you can make is to pay down your debt. If you have a mortgage agreement that allows annual lump sum principal payments on the anniversary, and you should have if you have a mortgage at all, do that first. Credit cards, if you use them intelligently, aren't the same as debt, they're a revolving credit line and you should try to organize your financial affairs so you don't carry a balance from month to month, you pay the whole sum off every month. If you can't do that most of the time, you're using credit cards the wrong way and buying things you can't really afford. The interest rates on credit cards are usurious; if you really need to make a big purchase, a loan from a bank or credit union is a much cheaper alternative in the long run.
But take care of yourself too, and have some fun. If you can make an extra $500 in bonuses every six months, good for you, and keep some of it back for yourself. Want a good digital camera? A new computer? A nice guitar? Some home renovations? Keep half your bonuses for yourself and you can have them all within a few years. Depends on your personal priorities, and nobody but you can decide what they are.
But above all, remember this. You have a certain level of income from your salary that you know you can count on consistently, and you've probably arranged your financial affairs with respect to that sum. The bonus is found money, you don't owe any of it to your spouse, significant other, children, or anyone else. It's uncommitted, it's yours and only yours, earned solely by your own merit, so nobody but you is entitled to an opinion about what you should do with it.
It's entirely your call. Your money, your choice. And I speak as someone who's been married for 25 years. Your total family income in salary is what determines lifestyle; bonuses, because they're not certain, can't be part of that calculation. They're a gift, and my wife and I have always agreed on that. My extras like that go into a separate account, what I call my FAT (Fishing And Tools) account, and so do hers, but I don't know what she calls hers. Salaries are household income, bonuses are not.