You could try looking up durability of waxed canvas. That has been a material used for centuries (millenia?) for tents and bags. A couple minutes of searching didn't yield immediately useful numbers. Some sites say waxed canvas can last decades. However, I think that's in context of bags which would only be exposed to the elements part of the time. One bag maker suggests that wax has to be reapplied every year or two. I found a research paper that demonstrates significant deterioration of beeswax with nitrous oxide and UV exposure. Clearly a greenhouse is going to have plenty of UV exposure. I'm not sure how to translate their numbers into a maintenance interval though.

So my mostly uninformed opinion is that this is good in that the materials are all biocompatible and renewable (if a plant based textile is used), but I would expect it to need regular reapplication of wax.

Glass would be longer lasting, but likely more expensive.