Wiring in star / wye / Y gives you a higher voltage and lower current.
Wiring in delta gives you a lower voltage and higher current.
Y also has higher resistive losses for a given amount of power output. (This is not too much of an issue with windchargers: Under a significant range of operating conditions some resistive losses let the blade speed up a bit, stay out of stall, and collect more than enough extra power from the wind to make up for the losses, giving you a net increase in collected power compared to a less lossy machine. Efficiency isn't an issue when the fuel is free - power collected and system reliability/costs are what matters.)
Delta has losses from circulating currents due to harmonic voltages that don't add up to zero around the loop. These may be very small if your waveshape is nearly a sine (or any of a number of other "good" waveshapes). Even if moderate, they are small compared to the resistive losses running near capacity in a charging application. But they are a pure resistive load, so they load the genny at startup and disproportionately at low wind speeds, when you need power the most. So windchargers are typically designed to be run in Y.
But matching your genny to your blades and wind conditions has a bigger effect on the amount of power you get than the loss difference of delta vs. wye. So once you've got your coils cast into resin and magnets chosen, you have to connect it the way that gives you better performance.
As Flux points out, you've wound your coils with few enough turns that you'll need to connect them in Y to get a decently low cutin speed. However, if you happen to wind your next one with too many turns, resulting in very low cutin speed and limiting the output at higher winds due to blade stalling, reconnecting in delta might be a quick fix to try before bringing it down and building a new stator.
Some gennies use a delta-wye switch to get more power out of the mill in high winds. You'll find stuff about that elsewhere on the board. They start out in wye, but above a certain speed a control box and set of relays switches them to delta. This lets the mill speed up and collect more power from the wind by reducing the load on the shaft, and delta outputs almost twice as much charging current (sqrt(3) = 1.732... times) for a given amount of resistive heat dumped in the coils, so it lets the genny run at higher power before furling is required to protect it from meltdown.
