Wow I guess it doesn't, just looked it up. Seems like a really basic feature to omit. Haven't personally used this but Mylio claims to have non destructive RAW editing with XMP files and runs on Android. Might be worth looking into.
Lightroom has no server mode at all. The subscription service won't help you because it's only between one desktop and multiple mobile devices all signed in under your account only. And the face recognition and keywording are NOT available on any Lightroom Mobile client. Only on the master desktop Lightroom application.
You might have a look at the Mylio service. I'm not sure if it will meet all of your needs, but the sharing is more flexible, it integrates with Lightroom, and it can tag from any device.
I have a complicated pile of storage:
The NAS has scheduled replication to the spare HDDs which are kept in a dock and swapped periodically with the ones at the office.
There are also regular backups from the NAS to Google Drive and GCS Nearline.
I'd really like encrypted sync/storage/backup but I trust Google with the Apps account so I haven't bothered.
Another solution I've considered though is Mylio, which claims to encrypt uploaded photos but since they haven't documented in any depth how their encryption works, I don't really trust them.
P.S. another entry in the blacklist is Bitcasa. They sold unlimited storage and advertised encryption but removed the unlimited storage from people who already purchased it and their encryption is easily broken on their end (they have a web interface that decrypts server side).
For images you want to keep on your iPhone make sure the colorspace is correct as already stated.
Free option: Just use iPhoto to keep an album of selected images. Kinda free option: Use Mylio (http://mylio.com)