The question Insurers ask is ''Does your named driver have any driving convictions''. As far as I know, only 1 of the big five charge for the speed awareness course, apart from that, NO. Its not a conviction.
Tell your insurer anyway, as non-disclosure may invalidate your cover in a claim. Most insurers charge 5-10% in the first and following year for a standard motoring conviction if he chooses to take the points instead of the course.