One of the personal story quests gave me a Letter of Commendation which is supposed to give 400 influence to my guild. Problem is, it didn’t actually do anything and my guild didn’t get any credit. Strangely enough, when I used the LoC I got the ‘2000 influence contributed’ achievement, though, so it seems like the system credited my account with influence gain, but didn’t actually give it to my guild.
And yes, I was representing the guild, and I only have one guild I’m in, so there’s no way I’m mixing it up.