Hi, I did a lot of research into Tea bag bedding and meant to do a comprehensive post re it but I never got around to it. Here are a couple of threads where we discussed it:
Substrate
Which substrate/nesting material is best?!
Basically, the sealant they use to seal teabags has plastic in it. The majority of teabag companies use this, you will be surprised how many that is and why they can't be put in your compost. Because of this, unless you know where the tea bag bedding is sourced from i.e. a manufacture that doesn't use a sealant with plastic in it or it is bedding that has come from offcuts that is kept away from the plastic sealant area I would not use it. I think there are safer options on the market.
I also had a teabag company follow me on Instagram so I messaged them and asked them at what part of the process is the bedding sourced from, I never got a reply.
Hope this helps.