How do you ensure iWork compatibility between iOS and OS X?

Switch to MS Office or LibreOffice? For all the criticism Microsoft gets in the Apple world, they at least understand the value of file format stability and backwards compatibility. Which is to say, as far as I know, you don't (or more accurately, you can't).

Sorry for the snarky response, it's reflecting my own frustrations with the way Apple has handled iWork updates and file compatibility (or lack of it). We updated people to the Mavericks version of iWork this past summer and we're getting so many angry calls from teachers and staff users who hate the change. Specifically they are very angry with how it's butchered their previous files, regressed to a format that's difficult to email, and lost features like text layout which made newsletters easy.

I had hoped this would be a one time pain point, after which the software would steadily improve, but when Apple released the Yosemite version of iWork, it felt like a kick in the teeth. They re-fixed the issue with files that were difficult to email, but you can't install it on Mavericks, so the only way to update is to upgrade, and that won't happen till next summer. Also, while you can open files from the Mavericks version, if you need to send a file to someone with the Mavericks version you need to export as Pages 09, then import in the Mavericks version.

I have no idea what the iWork engineers were smoking, but it's a joke and they deserve all the poor reviews on the app store.

I do think that Apple bully people into constantly updating. Treating anyone that dares to be on the previous release of OS X, iOS or other bundled Apple apps as second class citizens. In our organisation we need interoperability internally but also with lots of our clients. There's just no way we could use iWork, we'd be battling version compatibility on a daily basis.

If it had to be iWork, I would probably control software updating quite carefully and make sure you plan to upgrade en masse at a time that suits you.

Like you mentioned though, even though you can control your organization, you can't control outside of that. So the second your users upgrade at home, or their personal iDevices, you're out of luck.

This is hard to do on 1:1 iPad setups. If you are using VPP for the iPads and the users are in control of app installation and updating then there is no real way to control what version they will be using. They could immediately update to the latest version or be three versions old.

On the Mac OS side you could control the version by linking the apps to a company account and managing the updates with policies. If the Mac OS stations are also 1:1 then VPP would allow the users to update it themselves. I wonder if you could use an iPad Smart Group as a scope for a Computer policy to determine what their iPad has to see what Application version they need? I have never tried that but could get very complicated.

In our school district we have 1:1 iPads and MacBooks that go along with VPP. It is up to the user to update their apps and applications. If they are out of sync and have a problem then we tell them it is up to them to install the update. We have a few labs that we update as we have the time, have not heard any complaints about them yet.

Only fix to the compatibility issue from what I have been able to tell is upgrading your OS X devices to 10.10.
Due to the fact that I am at a 1:1 school that uses iWorks, and there is no way to prevent iPads from updating to iOS 8, I've really had no choice but to deploy 10.10 in all of it's buggy glory.

Yea... I feel your pain. The only thing I really have to add is that we are constantly pushing the Google Drive envelope as it seems to solve all of these issues for us, despite area where it's lacking. That said, we currently support Google Drive, Office 2008/2011 AND iWork (In all it's various forms). Office is our 100% supported suite but we're continuing to move to replace it with Drive as it's features mature. While we have iWork deployed and updated, it's pretty much up to the user to save it out in a compatible format to share.