[ QUOTE ]
What legal body recognizes their accreditation anyway? The rec climbers court?
[/ QUOTE ]
As far as I know there is no legal standing for accreditation for any instructors in any recreational outdoor skills like caving, rock climbing, ropes course, zipline, etc. "Accreditation" is given by professional organizations or associations for any of those activities. Same for rec tree climbing. For example professional experiential educators (incudes a wide range of outdoor activities like ropes courses etc.) have at least two professional organizations they could seek accreditation from.
TCI and GOTC represent two efforts to form professional organizations/associations to provide consistent criteria and guidelines for attainment and assessment of skill levels for rec tree climbing instructors.
I know many rec climbing instructors associated with either organization and I can only say good things about their abilities as instructors.
So... Jesse I don't think you can go wrong (agree with Dan) working with instructors from either group.
For pro climbers some of the protocols and gear used by rec instructors might seem strange compared to what you do in a work environment. I know several very good pro climbers who've gone through the TCI program. The upshot is they learned a lot from rec instructors who've put hundreds if not thousands of newbies on rope. Lots of wisdom in what they've found out doing that. The rope climbers then took that and enhanced it with what they already know from all their hours in trees on the pro side, it's a win-win.
Teaching rec climbing is not for everyone, it's harder work than you might imagine. Beyond everything you already know about tree climbing, a lot of it is people management mixed with the sheer logistics of rigging trees with large numbers of ropes and running the whole circus smoothly and safely towards a bunch of happy climbers at the end of the day.
-AJ