Tony, all I can say is that I've done a whole lot of climbing, and at the same time been misled by Yoga (as into hypermobility stuff) and also really educated by Yoga in ways I could never have figured out just from climbing.
The whole concept that the best training for climbing is climbing is shortsighted. It works up to a point... then one must open the mind to new things.
So I do not see that climbers have much to offer in knowledge to these ancient disciplines, rather I think it is the other way around.
And I agree with what Mr Cole wrote. Hi Scott!!!
Taking my yoga teacher training this month. It's a very old practice and climbing, while also ancient, has not a codification in the manner of , say, the Yoga Sutras.
Astrology is an ancient practice. Scientology is nicely "codified." Whether Yoga or Tai Chi is useful for climbing (in the sense of better than climbing itself, not better than sitting on a couch), I don't know, but it'll take evidence based research to convince me, not just old mumbo jumbo.
If people have fun doing it, great, lots of people like reading their horoscope.
Tai Chi (Tai Ji Quan), and climbing. my experience has been that these two practices do inform one another. I've been climbing for about 23 years and practicing tai ji for about 16 years. Tai Ji trains relaxed, efficient, whole body movement, among many other things. In the last 10 years or so I haven't done a huge amount of climbing but I've found that with my Tai Ji and Qi Gong training, I've maintained an ability to climb at a reasonable level, maybe 1 full number grade lower than when I was climbing all the time. What does climbing do for Tai Ji? Hard to say, an ability to focus on a physical discipline, a connection to the natural world... Learning Tai Ji is a long process, not unlike being a truly competent rock climber. Try it out and see if it resonates with you. I'm not sure that I would pursue Tai Ji if my motivation was solely to improve my rock climbing. Other Chinese martial arts like Shao Lin Gongfu might be more useful in terms of tendon strengthening practices.
If one is interested in applying Tai Ji movement principles to rock climbing, as an earlier posting noted, training with a teacher who understands martial applications would be useful. I have yet to completely integrate Tai Ji into rock climbing, and making rock climbing an "internal art", an interesting project though.