Hi, I can understand why you are annoyed, if you have been fobbed off.
However, I don't think you should use your knowledge of the payroll for your own leverage. I do payroll for a small team and personally I don't think this is the way to go to secure your own pay rise, as to me it would be quite unprofessional. I have seen similar things put through payroll, but I am in a trusted position and ultimately at the end of the day it is none of my business, all I need to concern myself with is that I work out their calculations correctly. Ultimately, I don't really care what other people get, good or bad, I just look after myself.
By all means apply for your own pay rise, on your own merits, not against someone elses weaknesses. Book a meeting with your boss to discuss how you have achieved your targets, been an asset to the company, blah, blah, and how you feel you deserve a pay rise but do not under any circumstances discuss another staff members package or bonus structure. I really don't think you will do yourself any favours.
Good Luck!