A few other notes about golf clubs whilst I'm sat with a nice glass of wine, just in case this is something that he might consider:
Most golf clubs are either owned by somebody (proprietary) or owned by the members. Ones owned by the members tend to more easy going and (as a general rule) likely to be better to work at. Members' club members are looking after their own interests, profits run the club rather than lining someone's pockets. (That's not a bad thing per se, but worth mentioning).
Golf clubs often cater for private functions, dinners, and various other types of event ranging from small to huge. You get far more experience in a golf club clubhouse than working in a bar/restaurant.
If he gets a food hygiene cert he'll be able to do some foody stuff (pretty sure on this), which is another good thing to experience. Not sure of his age, but at 16/17 he can work behind the bar if supervised, all good experience.
Then there's a Pro-shop. They often need a bit of help, collecting range balls, manning the shop, and even taking a buggy onto the course to sell food and drink (doesn't happen everywhere, but it's a fun thing to do).
There are greenkeepers too. Early start, very early, but if he likes fresh air and doesn't mind a bit of graft that's another aspect of working at a golf club.
I've worked at three golf clubs, and good people who are smart, engaging, reliable and just get the job done are worth their weight in gold.
FInally, golf clubs are all over the country, and as I've said, they are very often looking for staff. If he's worked at one and got a decent idea of how things tick he'll be highly capable of working at any of them, so he should always be able to find a bit of local work.