You are correct when you say that a Group Captain Administrator does not decide such matters, but a Group Captaiin is an implementer who makes things happen.The documents posted by Glider on the first page of this thread show that this was only a proposition, not a decision - a simple RAF administrator hardly had the authority to decide such matter - and decision was not yet taken on the matter nor in February on the 5th meeting, nor even in April 1940, and there isn't the slightest clue how many, if any of the listed 21 stations would be choosen for 100 octane fuel shipments, and wheter they were supplied or not.
However the paper you posted is a different matter and has nothing to do with the choice of the stations. The paper you posted was in my post 2 and is the instruction from the Chief of the Air Staff that fighters and Blenhiem Bombers should start to use 100 Octane fuel.
When the Chief of the Air Staff requests something he is not asking for something. ACAS stands for Assistant Chief of the Air Staff and we can be sure that he wouldn't do this without his.
Please take care with your quotes and postings, mistakes like this can cause confusion.
By the way did you get anywhere with the hunt for the Australian Paper it would solve a lot of questions.