From a tactical point of view, no.
From a philosophical viewpoint, maybe. Druids are supposed to be one with nature, and a bow and arrow distances one from his prey. However, Tarzan was one with nature and he used a bow.
From a cultural viewpoint, yes. Druids come across as being cultists, not hunters. The people hunt food for them. They deal with their people's spiritual, cultural, and religious needs, and, in return, the people give them food and other necessaries.
From a game balance viewpoint, maybe. Druids perform the same role as a cleric in a party. If druids can use bows, then what makes them different from a ranger? On the other hand, I don't know that it would imbalance the game to give them a bow, especially if your druids in your world don't have the cultural framework described above.