Why is it listed as a bonsai on this site if it's not? Or is that just a common term for this tree?
Good question to which, to be honest, I do not have the answer. You'd have to ask the owner of the site.
Ih my opinion, this plant isn't suitable for bonsai. Looking through Google images, I cannot find any that looks like a real bonsai.
Well... at least you found the care guidelines. Hope that helps.