It seems that Facebook has changed the ability for Facebook page owners to tag people in their photos.
As this post is written (June 2015) this is a work around that I’ve found that works. It’s a pain the backside to have to do this and can only be done from a computer rather than a phone app but it does work.
Step 1 –
Go to the Facebook page post and right click the image and open in new tab. If you don’t do this then you’ll only have the ability to tag other Facebook pages and not people.
Notice the ‘tag photo’ button on the bottom right? Click that
Voila! you can now tag people in the photo!
How To Tag People From A Facebook Page Photo
So at least for now, that seems to work fine, Facebook are continually changing their software so how long this will last I just don’t know. Checkout more Facebook Page Tips here.