I haven't been exposed to too much AFIS R/T, but as far as I understand, the AFIS R/T can provide traffic *information* about anything that happens in the circuit and on the runway, and gives *instructions* with regards to anything that happens on the apron and taxiways. The border between the two obviously being the runway hold lines.
So you would have gotten taxi *instructions* to the hold, but from then on it's your discretion; the AFIS controller just requests you to inform him/her when you cross the hold to line up, so that he/she can *inform* the other traffic of your intentions.
Obviously from this point on the normal regulations apply: You are not supposed to cut off any traffic that's established on final.