Hey Stacey,
I’ve yet to find a Canadian company for this. However, rather than going the compostable route, you could source reusable cotton pouches which are sealable with a drawstring. These are more expensive, but you can get a lot of use out of them. Here’s a link with an example: https://store.kombuchakamp.com/cotton-muslin-bag-3-pack.html
I’ve used something similar to this for both gifting tea blends, and brewing myself, and have been very happy. If you go in this direction, make sure to order unbleached cotton.
Liza