Here is how I track bonuses, night incentives, etc:
I have a standard worksheet that I've created in a Word doc. The worksheet is specific to each location via the address, visit number and the security code.
The sheet has all the pertinent information I need as well as a comment section and directions area.
I have a spot that I write in the night eligible dollar amount and any bonus amounts. There is also a spot where I write in the date of the invoice, the invoice ID and last of all the invoice amount for the visit.
The sheets are hard copies that I file in a folder for that particular month. When I receive my check, I review each visit that I've been paid for the amount and incentives.
It works for me. It was something I learned from reading all of the comments and suggestions from this very forum!