680.43(E) All metal parts associated with the spa or hot tub shall be bonded any of the following methods
(1) The interconnection of threaded metal piping & fittings.
(2) Metal-to-metal mounting on a common frame or base
(3) The provisions of a copper bonding jumper, insulated, covered, or bare, not smaller than 8 AWG solid
Doesnt look like its changed..