The best explanation I’ve heard is that the biblical names connote something larger than life, and thus the names of these larger than normal-sized bottles are meant to reflect this.
Way back in the mid 80s, Clos Du Bois made some extremely large bottles of Marlstone. They were even larger than a Nebuchadnezzar. People would ask, "What do you call this size?" We took to calling them an Atom-boam.