Ahh! Now you've blown out the thing on the brown wire!
Also, you'd have to adjust the component values on the AC side -- for a high voltage output (nearly full rectified AC, which is 160VDC, from 120VAC), you'd need a pretty large C1 and small R0. Although, the current will be lower as well, so the change might not need to be very large. And therefore C2 can be much smaller, maybe a few uF at most.
But yeah, guessing the sensor thingy can't handle much over 30V. So, the circuit largely has to be the same, up to the transistor being a HV type.
Nice thing is, even with the low voltage supply part hanging around, you don't need to have the neon drawing current from that supply. You could tie it back to the AC line (L) instead, through a diode, so it only draws forward current, and only when the AC line is positive and high voltage, and while D1 is conducting (so that the transistor is pulling towards "-V" which is connected to N at that point in time).
Extra filtering between R5 and Q1 is probably a good idea (maybe a 0.47uF across D3?), otherwise the neon will blink at a rate determined by line frequency minus rotation frequency (usually a few Hz for typical induction motors; if it were a synchronous motor, it might not light at all because the phasing could be completely wrong!).
Tim