Anything you earn as a bodyguard in freemode(selling cars to LSC, robbing stores, etc) is sent to the VIP. You do get a $5k salary from the VIP awarded periodically(I think it may be a game-day but I haven't paid close attention) which decreases by $250 each time the VIP dies, even if it is of their own volition or killed by an NPC/gang fight/etc. In exchange you get access to a Buzzard, Turreted Limo, and a few others as well as your health regenerating faster and ammunition replenishment from the VIP. I haven't played much with it but I believe most of that is done through the interaction menu.
As a VIP, you can engage yourself and your bodyguards into various profitable tasks like stealing cars, picking up packages, and others. Some of these pay well(over $20k per player) and some of them do not. You can make over $100k per hour if your group is constantly engaged in activities, but you can make almost as much on your own anyway. It's a cool feature, but you're not really missing out on anything great in my opinion if you aren't part of a group.