Brute Bonnet's best moveset in Pokémon GO is Splash and Struggle, with 11.79 damage per second, and it can deal 434.3 damage before Brute Bonnet faints. This is true when battling in neutral weather.
All Brute Bonnet movesets ranked
Here is a complete list of Brute Bonnet movesets in Pokémon GO, ranked by their DPS and TDO. You can change the weather and the opposing Pokémon.