Pick one: store the powerups or the bonuses they confer.  You can either:

1. Remove the addedBombs, addedBombRange attributes, along with their setters.  The getters (e.g. getBombRange()) will instead iterate over the list of powerups and return the result.

2. Remove the list of powerups and keep the attributes.  Get rid of the setters too, or make them private.