We're at the point in our 2-players-and-a-GM Dungeon World game where one of the PCs is working with a rather regular cast of friendly NPCs in addition to the other PC. This means that the PCs don't always get to explore their Bonds with each other during the course of sessions, kind of starving them of XP.
One of the players proposed the idea of his PC making a bond with an important/regular NPC in the campaign in the same style as a PC-PC bond, where it can be used for Aid or Interfere, or resolved by mutual agreement at End of Session, thus rewarding the player who cashed that bond in with XP. While I could see where this could be useful to represent long-term relationships with NPCs, and it's not without precedent in the PbtA universe as a whole (Fellowship has PC-Overlord bonds, for instance), it does raise concerns about administratability from the GM side, given the XP value DW bonds have attached to them (vs. their Fellowship counterparts).
Are my concerns with adminstering this sort of thing evenhandedly overblown, or am I correct to be leery of this idea, and how could I mitigate such issues if they do turn out to be a concern?