When we stayed at the Pullman Berlin Schweizerhof they specifically said they couldn't upgrade us due to lack of availability, I then checked their website which showed suite availability and successfully managed to obtain the upgrade to the suite, the only thing we didn't get was free minibar (which is advertised as included on accor's website) but that didn't particularly bother us

When we stayed in Mercure in Norwich (UK) they didn't seem to have any awareness of the Le Club, I asked about a drinks voucher and they just said oh but you've got a drink (the rate we booked included champagne) they also had no clue about upgrades and getting 10% off drinks at the bar was also a struggle. I'm going again in April, I'm hoping they'll have better knowledge this time!