The bug affecting guild bounty acceleration was fixed!
There is a bug in unlocking Guild Bounty Missions and ANet has advised players not to spend any influence to speed up the process. Does not seem to affect standard unlocks, though.
There is a current problem with Guild Bounty Missions and they are not functioning correctly.
We would advise guilds not to spend the influence to speed up the process to unlock the Guild Bounty Missions until such time that we are able to fix this error. We will keep you updated in this thread with regard to that fix.