I can see why you are upset op, and originally I was going to say how unfair it is and yanbu.
But...dh is a coach for the one of the ds's schools football team. All the dc (about 20 in every age group) get to play one match every fortnight/three weeks. Except for ds2 and a couple of the others coaches kids, who get to play a match every week.
A couple of the parents complained. Demanded that the coaches kids only attend the same number of matches as the others, as it was unfair and that the coaches were 'taking perks' at the detriment of other kids and abusing their positions and all sorts. Nasty.
Dh gives up every Thursday night (3ish hours) and every Saturday morning to take these kids training and to matches. Plus had to give up three full weekends in a row (8 hour days) when he first applied to do all the necessary training. Full enhanced CRB check. Extra First Aid training. Regular coaches meetings to plan events and matches and awards throughout the season.
It's voluntary. If it wasn't for him and the other coaches committing to the club and volunteering, it wouldn't exist at all. So yes, the rule about the number of matches each dc gets is bent for the coaches.
The other parents can either suck it up or they could, of course, always volunteer their own time and spend approximately 8 hours out of their own week doing so - then they could get the same wonderful perks as the others 
I don't think yabu op. But I do think it's 'reasonable' that volunteers get perks or rules bent for them, within reason, that the school or organisation couldn't do for everyone.