I didn't tutor ESL, but I did do a ton of international/cross-cultural volunteer work before being accepted to med school. I wrote about it in my personal statement as well, so it came up in all of my interviews. I was able to pull a ton of stories/examples from those experiences which was invaluable in demonstrating my ability to problem solve, communicate across cultures, work with others who are different than myself, etc. Most schools concentrate on diversity of some kind, so that definitely plays to your advantage. Make sure you connect your tutoring experience with your ability to work with diverse populations. It'll look good and if it is a prominent part of your application they will likely ask you about it.
Some interviews are really short, so it just depends on what there's time for and what else interesting you have going on in your application. Good luck!