As a student, is it okay that my mentor and I are in different time zones?
Yes, it's okay. Time zones make life a little harder, but, ultimately, it's not that big an issue.
Definitely. We have businesses and students working together from opposite ends of the world. The unique thing about Acadium is that there are no barriers with regard to who you can work with.
As long as both you and your mentor are aware that there is a time difference between you two, and both of you are okay with that, then there's no problem. All you have to do is make sure that you have better time management so that you can still do as much as you can and maximize your apprenticeship.
You can decide upon weekly meetings that are at reasonable times in both your home countries and work from there. Sharing a calendar might also help with making sure that communication doesn't become a problem.