sjeanl,
I guess what is meant here that in the first instance they are referring to those schools such as ETPS, USNTPS, NTPS etc, that provide short and longer professional courses in flight testing. Some end up with a post graduate qualification, but some don't. However I know that not being a graduate from these courses wouldn't prevent someone from being a member, as I know experienced engineers that aren't graduates from these schools, but would be eligible. The best bet would be to contact FTSA direct and clarify with them any concerns that you might have.
There might be someone from FTSA that can further add to this.....