I just did a survey with my friends from different countries-
Here are the variations:
Venezuela- cierre
Mexico- cierre (my friend also said they would not use cremallera)
Colombia- cremallera
Chile- cierre
Nicaragua- z?per
Ecuador- cierre
Actually in Colombia both are used my friend just came and told me after having thought about it. It's probably the same in Venezuela both words most likely are used.
I have one more addition from a friend here. In El Salvador they use z?per.