Is it an Equal Pay violation to pay a bonus to one employee and not the other in the same position?

I was hired 2 1/2 years ago in a management position. There are two of us at the location that share the same management title and we have the same job description. When I was hired, I was paid 20% less than my counterpart and was not eligible for the Management bonus program that he is eligible for.

We essentially have the same amount of experience but I have a Graduate degree, and my counterpart has no degree. After working a year with the company, I found out that my counterpart received a 25% bonus for the Management Bonus Program. I approached my manager and asked why I was not eligible for the same program, I was told that it would be discussed in my next review. To appease me I was told I would get an ad hoc 3% bonus.

This year my counterpart again received a 25% bonus, I have now been told that it will be looked at next year and I didn't even receive a 3% bonus. All my performance reviews have exceeded expectations.

Is this an equal pay violation?