After giving it a test, I find Hamstring works correctly on all active skills but Arrow Bomb. According to what Hamstring skill description states, I can't see why Arrow Bomb is excluded from the ability of slowing an enemy's movement speed given by Hamstring, unless it's impossible to simultaneously apply stun and slow to an enemy.
it's been this way since I started playing, and I reported it before so I think at this point it's intended.
