If Dennis had mentioned Venetian Glass, don't you think we would have guessed on Venice? Buffalo can be most NA tribes......
But it has to be specifically Venetian Glass, where no other resource currently in-game has such a description, and Buffalo was a lot more central to the life of the Sioux than Venetian Glass was to the Venetians. I don't think Venice will get in, and even if they did, a UA based on Venetian Glass would be...strange to say the least, given all the other things Venice was notable for, while representing the Sioux without some nod to their reliance on the Buffalo is almost unthinkable.