If it's a bonus you get on a yearly basis, it is absolutely part of your salary. If it's a one time thing, you probably should not count it.
Let's say you have an employment contract, get an annual salary, and are given a year-end payment that is likely a percentage of your base pay and is similar to the amounts given to your co-workers and others with your job, in your industry. Compare and contrast this with a one time payment based on a random drawing of numbers in a zero-sum competition with a few ten- or hundred-thousand other people.
My response was directed towards the poster who said that bonuses should be counted as salary since taxes are paid on it. That's clearly wrong. And as I've maintained, if management can choose not to pay you the bonus, then don't count it as salary.