Please let me know if this all sounds right and where I can improve safety.

I have a Sundance Capri spa (a 3 wire appliance), and put 3 lines from the tub to the 50 amp gfci sub-panel (red, black, green) 6 ft from the tub. The red and black to the gfci breaker, the green to grounded bus.

From the house I ran 4 lines from the main to the sub-panel (red, black, green, and white). Red and Black from the 50 amp breaker in the house to the sub-panel connection. In the main, I put the green and white both on the ground bus (like the other wires I saw in there). 1st question - Is that right? Then Green to the grounded bus in the breaker sub panel. Second question - Should the white go to the bottom of the GFCI breaker or to the neutral bus? The white coil from the breaker put on the neutral bus. The neutral bus stays unbonded.

Thanks much.
Thanks also to charger_1 for help with earlier questions.

I haven't heard from anyone on this forum but I would like to post what I found out elsewhere. The neutral / ground are tied together on the main panel. There's no other way. The white from the main to the sub-panel goes to the neutral bus, and that is where the pigtail from the gfci breaker also goes. IF it was a 4-wire setup from the tub then the white from the tub would go to the breaker itself...but with Sundance Spas, it is only a 3-wire setup.