It probably deals more damage than your regular bow. Was the case in MW and OB. Plus free arrows?
It most certainly wasn't the case in Oblivion.
Bound bow: damage value of 15
Bound elven, glass or Daedric bow had base damage values of 18, 18 and 21.
So at least 3 types of bows had a higher base damage and you could either add a custom spelleffect or get a preenchanted bow which tipped the scale even more in favour of non conjured bows.