Some people in my company have recently received year-end bonuses. However, I and my teammate did not. However, he and I not only were never told we were not doing a good job, nor written up or reprimanded in anyway, I personally have been told repeatedly what a GREAT job I am doing. Is there anything I can do? Like, request the criteria for who got bonuses, or ask why some people did, and I did not? Others in the IS Departement did, from another team - just not me or my teammate from our team (since we are the only ones eligible in the first place, since he and I are the only ones salaried on our team.)

Unless you and your colleague did not receive the bonus SOLELY because of a legally protected characteristic, such as race, age, gender, etc., this is not illegal discrimination. However, the employer has to know (assume) that employees will talk and that Bill will tell Joe about his bonus, then Joe will get upset because he didn't get one. If the boss just likes Bill more than he likes Joe, and that's the reason Bill got a bonus and Joe didn't, that's not illegal disrcimination.

To start with, you might start by talking to your direct boss. Maybe something like "Other team members have told me they got a bonus this year. Is there something I can do to increase my chances of getting a bonus next year?" You DON'T ask why Bill got one and you didn't. WHY Bill got one is not your business.