Just to follow up, only just got round to doing it, it undid fairly easily, came to torqueing up and got up to 90 deg which felt really tight, more than before, so stopped there. Double checked the 50NM on my torque wrench against the digital gauge (as didn't fit in the gap) so I know that was correct.Okay so confirmed. My engine CXGB and year is there.
One thing concerns me, to get 180degrees may be difficult/awkward as just turning the 90degrees was due to the spline head and lack of room (trying to keep the spline socket in the head).
Also wondering what prompted VW to change this ? My original tensioner when I removed the bolt was I reckon at 90degrees as was very similar to replacement tightness and had been there for 5 years.