How should I quit when I know my exit far in advance?

Hi all, apologies if there is already a post like this, as I tried to find one but could not.

Anyway, as a short intro, I am a second-year analyst at a middle-market bank in NYC. A few months ago I received a PE offer starting next summer once my two-year program ends.

With that being said, I plan on not telling anyone until it comes time to quit because I would most certainly get a smaller bonus next summer (not sure if all banks work like that, but that's the way mine does).

These leads me to a few lines of questions:
1. When do I quit (or put in my notice)? When I get my bonus number? Or when it hits my account? Has anyone heard of anyone quitting after getting their number then a bank rescinding the bonus?
2. As I am in a two-year analyst program, I expect to be promoted to associate during my compensation discussion. This would lead to a promo bonus along with my full year's bonus. If I don't quit until my bonus hits my account would I have to pay it back? How does that type of thing typically work?

As of now, I am thinking about putting in my notice when I get my bonus number so I don't have to deal with the headache of paying back a promo bonus, but would love to hear some input from people who have been in a similar situation (or know people who have).

Lastly, sorry if any of my post sounded like I was gloating/bragging, I tried to tone it down as much as possible. I appreciate your help!