I'm specifically trying in Illustrator CC 2014 and my custom workspace from Illustrator CC doesn't show up. I've manually synced on both sides and no luck. I assume this issue applies to all of CC 2014. Thanks for any help!
You are correct. You cannot automatically sync the workspaces present in Illustrator CC as this feature is available only in CC 2014 apps. So, you need to transfer workspaces from CC to CC 2014.
Check the below links for how to do so.
Let me know in case you still face any issues with it.
That worked, thank you Arpit!