I pick the talent, then a square adjacent to Bonnie Anne.
When it’s Bonnie Anne’s turn, she blasts in that direction.
However, Bonnie Anne will not take her shot under the situation described below (which is consistently repeatable):
If the square I chose is occupied by another companion.
And that companion moves to a different square, before Bonnie Anne’s turn.
I targetted a square with bomb traps that was occupied by another character. They went before me and ran across the table, I was surprised that when it came my turn instead of bombing where I had selected all my bombs targetted where the other player had moved. In terms of Bonnie Anne, scatter shot only works when Bonnie Anne fires it on a square adjacent to herself, so if another player is on that spot and moves and then it comes to being her turn and they aren't adjacent to her anymore she can't fire. This does seem to be bad programming as mass attacks should target the squares and not those who are upon it.