3 wire spa (no neutral/white) is connected to a gfci spa disconnect.  Within the disconnect, a white pigtail is connected from the gfci breakerto the neutral bus bar (separate from the ground bar). From the gfci disconnect to the main panel breaker (the 2 pole breaker in the main panel is NOT gfci) there are 4 wires.  To connect from the disconnect to the main breaker, does the white wire get connected to one of the neutral terminals of the breaker, or does it get connected to the neutral bus bar in the main breaker?