We are with the TLCC, I haven't done the training, but my husband has and he enjoyed it and learnt a few things along the way.
There are lots of members who join the TLCC to do the driver training and then don't renew. I believe the 1st year membership is cheaper than doing a commercial course, but don't quote me on that.
Most commercial courses have some sort of governing body accreditation, as do some 4WD clubs courses.
Also being a member of a club can be a good way of getting out on the tracks, but all clubs are different and have different dynamics and goals, so it's best to attend some meetings and find the one that best suits you.