That is exactly the case, the elves are indeed bonded, but since it was by contract it is technically by magic. The spider bond, though probably not enough to make Sericon into a spider king, is to ensure that even in a space devoid of magic they can rely on a natural and evolutionary bond. It’s the difference between using magical whispers to talk or the telepathic bond between silithid.
I just must figure out what social creatures to add next, I can’t decide between raptors, wolves, hyena, ect. My first decision I guess must be between mammal or reptile…