I am wiring an indoor bathtub which has a "blower" unit. Since it doesn't actually circulate water but blows air instead is this considered a hydromassage tub by defintion?

The reason I am asking is that there is no bonding lug on the motor - in fact everything seems to be plastic. The plumbing is all plastic pex until it reaches the valves. I was planning to run the #8 solid from a grounding clamp near the valves to the motor but since there is no lug on the motor...

Should I connect the #8 solid to my equipment ground at my receptacle? I realize that is not the intent of the code to ground metal parts, rather to bond them together.

Also, the manufacturers instructions mention nothing more than to install a dedicated GFCI circuit and mention nothing about bonding etc.

It doesn't sound like there is anything to bond and nothing likely to energize the valves. I don't suppose it would hurt to bond them to the EGC but there is no code language I know of to require it.

The best thing to do when you are not sure how to define an assembly or a piece of equipment is to locate the UL marking and listing. Even if the product is investigated and tested per one of the other NRTL, it will have to meet a particular standard.

For your particular instances, look for UL 1795. This would mean the tub assembly is listed as a hydrotub. Once you know that, then you can apply the requirements of Part VII of Article 680 and the UL guideinfo use and installation requirements.

In my opinion, no bonding is required per your description of the installation.