As I understand it.... NPPL holders can tow gliders. Nothing gets written on the licence.
EASA licences have entries for extra items.
Unless the gliding club CFI is qualified to the new licensing standards, he/she cannot certify competence, the fees payable to qualify have deterred many suitable candidates from becoming examiners....
Come 2018, there will be a bit of a problem, and betcha the date gets pushed back again!!!
If you have PPL(A), you may have difficulty getting a towing rating, so you will have to get an NPPL to fly the tug...
Unless you have an FAA licence maybe??
The figure of 15 tows was a club requirement perhaps, the 6 tow thing is a bit of an historical item!! That was introduced after a few fatal upsets.... maybe in the '30's.
I believe our current CFI was given special permission to act as such at a single, winch launch only site, and has no power flying licence.
Aerotow launches have to be arranged on occasion for exercises such as full spin training, otherwise club members have to travel to other clubs for instruction! A tug and driver must be obtained, it would be easier to hire a tug for the day with a resident member flying it.