You only appear to be able to target the base block of the burst spreader which is not an emitter itself. And since you cannot seem to target any of the 5 nodes on the spreader you cannot link receptors or funnels to them.

(you probably figured this out 10 days ago)
Right, so this is an artifact of the burst spreader not having a nice hitbox, the link will work fine on a per side basis, so if you click the north side of the base, you will retarget the north side of the spreader.

I guess it could stand to have a nicer hitbox.