Hello
Since banana peels don't contain nitrogen you should be reasonably safe to use at least once a week, but dilute the tea because it's usually pretty concentrated, like 1/4 cup per gallon. Since it's not a complete fertilizer, if your plants are still needing some nitrogen you'll want to add an ingredient that contains nitrogen to your tea brewing.
Also when you're done with the brew you can save the banana peels, dry them, cut them up and now you have a nice banana peel powder for later use.👍
If you're doing an a.c.t a good recipe is vermicompost,molasses, kelp meal, fish hydrolysate.