I stay there a lot - about once a week, and I'm a RA.
I usually get club lounge FOC, but it can be hit and miss, and seems as though it depends who checks you in - and indeed whether you're on a paid stay or points. I would say that paid stays, always booking the cheapest room gives me club lounge 90% of the time, whereas reward nights will be more like 60%.
The usual excuse is that "we are busy so can't let you have it this time" - but it's worth challenging on a paid stay. But on a reward night, it will depend on your overall status, or perhaps in this case, the lack of regularity at the hotel. FWIW you should get free internet (and movies), and an upgrade, but don't "expect" more as you will be disappointed.
Free booze and canapes are worth having in the lounge, as is the free complimentary breakfast in the club lounge (continental). I have (although rarely) been offered to get access (when it has been denied) for around £30 plus vat. Not bad value if you really do use it (ie drink !).
Hope that helps
RB