Bit of both. The Conjuration perk "Mystic Binding" conjures stronger weapons, but you're gonna need to put points in One-Handed to use Bound Swords effectively. Same for Two-Handed and Bound Battleaxes, and Archery for Bound Bows.
Also, Conjuration perks past Mystic Binding also offer a perk that casts soul trap when you strike with a bound/mystic weapon, and another that banishes daedra.