Effectively never. The problem is that Tesla Superchargers deliver DC at around 400V (future superchargers will probably go higher). Changing DC voltages is hard, and the equipment to do it isn't the sort of thing you're going to put on a motorcycle.

The EVs pack voltage has to approximately match the input voltage. The pack Voltage is approx #ofCells x Vcell. The cell voltage is determined by chemistry (around 3 V). So to take a DC fast charge, a motorcycle would need a lot more cells than they have*. They could try to make a bunch of "skinny" cells (same voltage, but not holding much energy), but that's not very weight or size efficient.

Further, Tesla doesn't have any interest in SuperCharging motorcycles. The CEO is against them for safety reasons, so Tesla won't make them. Without a Tesla vehicle to support, Tesla has no interest in shifting the Voltage down on the Supercharger side.

[*] Zero motorcycles uses a pack Voltage of around 100V.

Electric motorcycles don't really seem to catch on. I wonder why?

@Schwabilismus I think bc they are mainly for entertainment in the US, the pollution argument holds less weight. Also the ones out so far aren’t great - held back by current battery density.