My bunk dominated in capture the flag??
I'm reading DEAR EVAN HANSEN, where two friends has a conversation as below on the first day after summer break.

A: How was your summer?
B: Well, my bunk dominated in capture the flag and I got to second-base-below-the-bra with this girl from Israel who's going to, like, be in the army(B is a Jewish).

What does it mean "my bunk dominated in capture the flag" here?

Question

My bunk dominated in capture the flag??
I'm reading DEAR EVAN HANSEN, where two friends has a conversation as below on the first day after summer break.

A: How was your summer?
B: Well, my bunk dominated in capture the flag and I got to second-base-below-the-bra with this girl from Israel who's going to, like, be in the army(B is a Jewish).

What does it mean "my bunk dominated in capture the flag" here?

Answer

a 'BUNK" is  a narrow bed.  Bunk beds are beds that children have that are one on top of the other. 
A bunk at a summer camp is a group of kids who live in a cabin together.

Capture the Flag is a game  where there are two teams. (Often played at camp) Each has a flag and the point of the game is to 'capture the flag" of the other team.
https://en.wikipedia.org/wiki/Capture_the_flag

So your sentence means that the bunk (the group of boys who lived together at camp) were better than the other bunks at the "Capture the Flag" game.