The same very general principles still apply to installing and wiring a spa pool.
Over here, the feed from the supplying switchboard, must be from a dedicated Residual Current Device(RCD), this is the same as a GFCI, although I am not sure of the trip current, that you guys use over in the US, we use 30mA, for personal protection.
The problem of Bonding all of the metallic pipework has been alleviated, by the use of Polyethylene Pressure pipe,but all metallic enclosures(controls housings,etc),must be bonded by at least a 4mm2 wire.
All light fittings that are installed in a
pool area are OK, as long as no person can touch them while being immersed in the pool,or are standing around the edge of the pool.
For any light fittings,actually in the pool, over here, they must comply with IP68 of IEC 527,this is the code for ingress-protection(dust and water).
What does the US use for the same type of code?, with respect to weather and water-proofing?.