MY iPhone 6 has 50GB of stuff on the Phones storage but only 17GB of data are being backed up to Icoud Why?????

See this article:

What does iCloud back up? - Apple Support

Note that:

Your iPhone, iPad, and iPod touch backup only include information and settings stored on your device. It doesn’t include the information already stored in iCloud, like Contacts, Calendars, Bookmarks, Mail, Notes, shared photos, iCloud Photo Library, My Photo Stream, and files you store in iCloud Drive.

and

1. If you turn on iCloud Photo Library on your device, your photos and videos are already stored in iCloud, so they aren't included in your iCloud backup.
2. Your iCloud Backup includes information about the content you buy, but not the content itself. When you restore from an iCloud backup, your purchased content is automatically redownloaded from the iTunes Store, App Store, or iBooks Store. This also means that music you may have imported from a CD via iTunes is not backed up. You will have to resync this from iTunes.

When you go to Settings > Apple ID (top) > iCloud > what does the storage bar at the top reflect? Is it showing the increased storage of 200GB? If not, try logging out of the device, briefly, and log back in.