Notes sync problem iphone 6s yosemite

I just upgraded from a 5s to a 6s and am having trouble syncing notes between the new phone and my mac mini running Yosemite.

I understand the new Notes program won't work with Yosemite, but I do not want to upgrade to El Capitan (my set up is non-standard with RAID software, so upgrading is a pain--I went from Lion to Yosemite last year, having skipped Mountain Lion and Mavericks).

So I'm using the old version of notes, which always worked on my 5s. But now, I can't get new notes on the phone to show up on the desktop or vice versa. Meanwhile other syncing seems to work ok--calendar is fine, for example.

I have not changed the settings for Notes or iCloud so I don't understand why it isn't working.

Neil