Qualifying for PPG Tandem with ASC 
To do PPG tandems you need the following, as listed in the Basic Flight Instructor (BFI) Application:
http://www.aerosports.org/forms/basic-flight-instructor-application
1) A minimum of 35 hours flying.
2) A minimum of 10 hours in training/flying tandem/dual.
3) Have a referring BFI recommend you.
4) Have a second signature from an AFI (Advanced Flight Instructor).
5) Pass the FOI, oral, and flight tests. Here is a study Guide for the Fundamentals Of Instruction (FOI):
6) The oral is that you fully understand part 103:
http://www.ultralighthomepage.com/FAR.part103.html
And you fully understand the ASC exemption:
http://www.aerosports.org/training/exemption-9785
7) Send in membership application to ASC with payment of $30 annual fee.
8) Fill out ASC BFI application with payment of $100 annual fee.
9) Follow the stipulations of the ASC exemption.
A) Maintain annual ASC memberships.
B) Be familiar with the provisions of the exemption.
C) Inform your student/passenger that the tandem flight is conducted under an exemption granted by the FAA.
D) Inform your student/passenger that the foot-launched, two-place powered and unpowered paraglider or hang glider does not meet aircraft certification standards set forth by the FAA.
E) Must have in your personal possession a copy of the authorization issued by ASC and a copy of the FAA exemption letter.
Additionally, expect to pay the BFI and AFI a few hundred dollars each for helping you to get this done.