Does anyone have a straight answer to what this term means and how it applies in the game? Everyone has different answers.
It's your pupils TB for them. Just my own observation. Not an exact answer. Everyone has their own way of describing it.
It's the max cash bonus that your pupil can receive from a single hit due to having you hired. So, if your max bonus to pupil is $1 bill, then that means that the maximum additional cash that your pupil can get from a single hit from having you hired is $1 bill. The max bonus to pupil is obviously very misleading because the max bonus to pupil is maxed out usually very quick. This means that in actuality, you don't give near $1 bill to your pupil. So after about 75 mill max bonus to pupil, it doesn't matter anymore to anyone.
I believe it is actually the cash you pupil makes when selling you. Sorry guys but it is not related to tutor plunder bonus at all. If I bought you, I would make $1b when I sold you.