Mother Talzin and other Nightsisters use something called Magick, a mysterious aspect of the Force. Some claim that it comes from Dark Side, some that it is a gift from Winged Goddess, some that source of its power came from ichor in the depths of Dathomir.
Powerful witches like Talzin have the ability to transfer to something called the "spirit world", with their body disappearing from the physical realm. With some effort, Talzin could also recreate her body as witnessed in her final fight against Sidious. What exactly this spirit world is and how did it operates is presently unknown to us, and likely never to be fully reviled because Disney decided not to pursue the Dathomirian plot anymore - the Nightsister cult is effectively destroyed and they have been for all practical purposes removed from further stories.
As for other users of teleport ability, they belong to Legends, with even less rules. Most notable examples are of course from the game Star Wars: The Old Republic, where this power limited itself to local transfers of either user himself or someone whom he wished to move. Unlike Mother Talzin, they could not use Force Teleport to travel long distances.