Yoshi.. where are my commendations reward at?

[Yukiko]

I think it the exact same method as well. If commendatiosn were given out in Wolves den then wintraders or those hireling them would likely get a ton of comms

I am getting more commendations in Wolves Den than in normal dungeons because when you are top in the list (Damage Dealer as example) you will be recognized.
In Fact when the golden mount was released many player who gotten it within some days traded them.

It does not only work with Wolves Den but still works with Dungeons or any other Content.
The Group of 4 need to join simultaniously (solo) the same dungeon.
It is a low frequently dungeon choosen, so you can be sure not many "outsiders" will join.

In early days it worked very well, because no one have done Wolves Den and you mostly gotten your friends into the dungeon, thats also how those win trades were working.