Spirit Law reads as a spell list for someone who cultivates a friendly relationship with spirits, aiding them and giving up offerings to them, and receiving their assistance. Spirit Domination reads as a spell list for someone who forces their will upon spirits and compels them to serve. Very different from a roleplaying standpoint, but spirits are spirits so there is some overlap between the lists for sure.
Spirit Trap forces a spirit into an item, while Spirit Binding requires the spirit to willingly cooperate (it's a utility spell, not a force spell), so it must be persuaded. The radius of the effect is probably greater, at least for low-level spirits.
Given the overlaps, it wouldn't make sense for a character to have both lists. Pick one based on the conception of the character and/or the role you want spirits to have in the campaign.