I have worked jobs where the best bonus over 5 years was $500, while the typical year all we got was a promise that if things go well there will be a bonus. I've worked other jobs where the worst bonus was $15000 (a really bad year for the company), and could be up to $50,000. This is as a regular engineer, management can get a lot more. The first company taught me at until the money is in my account the bonus is meaningless. The second taught me that they aren't just a rumor. Most companies don't even pretend to offer a bonus which is acceptable - at least I know what I will make.
I think everyone should make 2-3x the poverty level income (we can debate exact numbers), and everything after that is bonus. So long as the company pays a bonus most years it means in a bad year you have enough to live on and don't need to find a new job, while in a good year you have a nice bonus to buy nice toys.