The minimum across europe is EU-OPS, each state can have its own regulation if it is better (for the employee) than EU-OPS. As far as i know CAP 371 is not revoked and therefore still valid, but i'm afraid i do not know exactly how much of that is better than EU-OPS and which parts are not.
So yes, everyone has signed up to EU-OPS, however if some regulations in your local laws and regulations are better they may still be valid. I think many UK carriers were whining quite a bit to be more regulated than EU-OPS only.
We used to have that on blocks plus 15 minutes regulation as flight duty time as well (minimum in our local ops prior EU-OPS and still valid where EU-OPS is not applicable) and it is still in most union contracts for unionized airlines over here, some have 30 minutes which in my opinion fits better into reality than 15 minutes. However some do not want to lose 15 or 30 minutes of their yearly allowance of flight duty time each duty period and do not use it anymore, however it is still duty time (which has the higher 2000 hour limit) and not rest time.
By the way, if you sit for hours in the crewbus on the way to the hotel it might eat into your core sleep time which is "sacred" and therefore you must use a longer rest period to be able to get at least eight hours of uninterrupted core sleeping time.