To bombard is to attack, whether physically (with something like missiles) or metaphorically (with something like questions).
See the word bomb in bombard? That's a clue to its meaning. When a place is bombarded, an enemy could literally be dropping bombs on it. In the days of stoning, people were bombarded with rocks. A politician getting pestered with questions is also being bombarded. You could say a teacher who assigns a lot of homework is bombarding the class with assignments. Bombarding involves a series of attacks; one bomb or one question can't be described as a bombardment.