Yes. It must be that all things belong to one world because the very order of things created by God shows the unity of the world.
This world is called one by the unity of order, whereby some things are ordered to others (and whatever things come from God, have relation of order to each other, and to God Himself).
Therefore those only can assert that many worlds exist who do not acknowledge any ordaining wisdom, but rather believe in chance, as Democritus, who said that this world, besides an infinite number of other worlds, was made from a casual concourse of atoms.
From the unity of order in things Aristotle infers (Metaph. xii, text 52) the unity of God governing all; and Plato (Tim.), from the unity of the exemplar, proves the unity of the world, as the thing designed.