I think you are both wrong. Three dimensional (3D) means height, width and depth. Any two channel system that is worth having or is not broken will have all three dimensions. Three dimensional does not mean having sound coming at you from all directions as you would on a busy street. 3D has nothing to do with surround sound or home theater. It is what it is!
Look up the definition please!
Three-dimensional: adjective
having or appearing to have length, breadth, and depth :
a three-dimensional object.
I think 3D is a good descriptor for a sound system, and should definitely be included in the TCTDA. Good two channel sound is very three dimensional, as is live music.