Not great that the CC poured the Champers but took 10 minutes to bring it to you.
I sometimes use the call bell button in whatever cabin I am in if I need to. More so in Y at a window seat though but that's not applicable here. I don't do this often but my experiences over the years doing this have always generally been warm and passengers shouldn't hesitate to use them whether that's for a drinks issue or anything else that they deem may be important.
OT but as an example I was down the back in Y on an A380 and the passenger next to me was sleeping and I needed something out of my rucksack so I utilised it for this as I didn't want to disturb the passenger and the crew were passing back and forth anyhow and all done with a quiet smile.