This may not exactly be what you are looking for, but I hope it helps.
Bones in general would be associated with the Earth element. Bones have been used in a wide variety of practices; for example, bone divination and hoodoo.
In hoodoo bones are used for such purposes of drawing in money and for luck. I would associate this as being possible reason why the wish bone of a chicken is believed to grant the wish the person who get the bigger piece from the breaking of the bone between two.
Another use of a bone is a method of ancentral or spiritual calling. Being a sense of direct link to the spirit(s) in mind. Basically a method of necromancy. As well as pertaining to past lives and issues pertaining to death, dying, and the afterlife. It's not exactly a direct relation to necromancy, but that reminds of how bones can be used for purposes pertaining to the emotion and spirit of the inner self.
But of course the purpose of the bones will vary based upon the source. Magickal properties of bones concerning animals are based upon the properties of the animal in question.
Again I apologise for this not being exactly as you asked for.