Bereiter, by international treaty between Canada and Germany, is about equivalent to an EC level 1 riding coach- I have audited the Bereiter practical exams at Warendorf and I have qualified as an EC level 1 coach and the ridden requirements are very similar- basic level dressage and a 3’6" course of jumps, teach a group lesson, teach an individual lesson, teach a longe lesson, etc.
Reitlehrer, as explained, is a higher qualification, about equal to a level 3 EC dressage coach. In Canada there are fewer level 3 coaches and most of them are accomplished FEI riders as well.
I believe the equivalent to Pferdewirtschaftsmeister does not exist in the Canadian system, but the term, as translated by my former coach could be Master of the Horse or StableMaster. He has helped teach the courses in Germany and says someone completing this course would be expected to manage all aspects of an equestrian business, both practical and administrative.