I can't imagine it would be a problem, I have more yarn knowledge than chameleon knowledge though... Plastic-coated wire might possibly work better for your tee-pee, but it's pretty subjective. The only vague issue I could foresee is the yarn becoming frayed and not holding, or being tangled around feet, or ingested somehow, but only an incredibly determinedly accident-prone chameleon would think up those things. I'd say go for it, but keep an eye for the first few weeks and see if there were any problems.