No it seems to be coming out of the pipe at a joint. I have had a good look from the inside at the roof joint and can't see any water getting in there. It does seem to be slightly worse now it has been raining all night, but that doesn't explain the drips yesterday as it had been dry for 2...
I have a vent that exits to the roof and it is leaking in the attic space. I have no idea what this vent is for, the bathroom vent is separate, I need to know what it is so I can fix it. The vent seems to go down the pipe box at the back of the house, so can't see where it goes from there...