Q: people album multiple devices

Until Sierra is released no one can answer that - My guess is you will be able to but until the software is released everything is pure speculation

LN

With the currently released software faces are not synced from the Mac to iCloud Photo Library

Nothing about IOS releases affects the Mac OS X  in anyway

Again

Until Sierra is released no one can answer that - My guess is you will be able to but until the software is released everything is pure speculation

LN

.

The iOS devices are supposed to be in sync: Wait until the faces scan is complete. It may take a while with the originals in iCloud.

Have a look at the iPhone User Guide for the new iOS 10. It has just been published:

http://help.apple.com/iphone/10/#/iph9c7ee918c

And it promises:

People are synced among devices where you’re signed in with the same Apple ID.

 

The scan on my iPhone has not finished either, and Photos did not use any faces names from my iCloud Photo Library so far, that were already available from my Mac library.  Perhaps we will have to wait for the first update, but it is encouraging that syncing Persons is promised in the user guide.