That's encouraging – hard to imagine that it's much harder than teak.
That is exactly the issue, we don't know how hard the substrate you're using is.
Janka Numbers:
Carbonized Bamboo...1180
Bamboo...1410
Bamboo Strand...2790
Burma/Thai Teak...1000
Teak...2330
If this were my project, I'd just treat it like aluminum, you can drill it and you can thread it, that's a good thing.
Just take a sample of the bamboo that you're using and experiment by drilling several different diameter holes, thread in the insert and reflect upon the insertion difficulties. At some point in time you'll arrive at a solution that works for you.
As much as we all want to find an easy answer to our question at hand, sometimes experimentation is the quickest and most prudent method of evaluation.