I'm about to upgrade my Mac OS X to Yosemite version 10.10.1, but since its broken on icloud.com and iOS 8.1, I'm asking this question.
I have a critical Notes page in my iCloud account which is there, at least on my iPad which does not have 8.1 installed, which I was trying to access on my macbook via the Notes application and icloud.com. Neither are showing this note.
What could be the problem? I've already synced by Google accounts too, on the OSX Notes at least.
Best Answer
OS X Yosemite and iOS 8 have changed the way iCloud syncing works. With the introduction of iCloud Drive the file structure has been thrown open, but devices running iOS 7 or below and OS X Mavericks or below will not sync successfully once you have 'upgraded' to iCloud Drive. Have you done this? If so, the iPad won't sync.
To solve: First I would try what tubedogg suggested above, and then I would recommend emailing your critical notes to yourself and putting them in the Notes app in iOS 8 or iCloud.com. See if it syncs, and then I would say it is safe to upgrade to Yosemite.
If it still doesn't work you could always have a go at using an alternative notes service like Evernote or any other which features syncing.
I learned this from personal experience when upgrading to Yosemite iOS 8 and iCloud Drive. Hope it helped! ;)