So was Hook's land of origin part of the magical world, I.e., the Enchanted Forest, or was he from a different realm like ours?
Given their access to a Pegasus pelt, I'm going to assume Hook and the Jolly Roger aren't from our world. It's likely he's from the fictional England of Barrie's novel, similar to what they appear to have done with Alice in Once Upon a Time in Wonderland.
I'm inclined to discount the possibility of it being The Enchanted forest simply on historical/development levels, but they've played that realm so loose that it's impossible to throw it out entirely.