Hi Louie,
currently the only way to get certified is to do an instructor training with Bruce. He did Wu short form instructors training about 3 years ago so there probably won’t be another one for a while. That training was in England and was 4 weeks long.
He is doing Gods Playing in the Clouds instructor training next year.
You can, of course, teach without certification but the certification process really deepens your understanding of the material. Bruce has an article on the site about this – http://www.energyarts.com/teaching-energy-arts-courses-without-certification.
Yoke Chin lives in Sydney as well – http://www.energyarts.com/instructors/taichi-qigong/sydney/yoke-chin. She’s certified in a couple of subjects and I know she teaches Yang style. It might be worth talking to her about her experience.
Trevor