I don't believe it's really based upon anything. I think it's just meant to be your classic fantasy town setting, hub world-esque type area. I believe there were posts a long time ago talking about what worlds were based on what, and I believe they all said that it was just based upon being a random city, fantasy type place.
Wizard City is based on Viking lore. Bartebly is based on the tree, Yggdrassil. Dragonsypre is based on Greek-Roman lore with a mix of Russian culture.
Well if you’re asking about lore Merle Ambrose went out to discover different types of schools for wizardry. He found fire , ice and storm which were the magic of the titans. But then we continued to find schools which were manipulating the forces that make ones self which are death, life, and myth. That’s just why the schools are there that we have other than death school because malistare broke it away from ravenwood but there is a whole other story about that! For a complete run through about wizard city’s lore I would watch this video by Kenneth FireBlade