Cant get iOS 10.2.1 and OSX 10.10.5 devices to allow phone calls from OSX
First, register your phone number with iMessage. It appears that it is not registered from the screenshot you provided.
See how here: https://support.apple.com/en-us/HT201349
Next, ensure your Apple ID is signed in on both devices.
Go to Settings &gt; iCloud on your phone and check your Apple ID here:

Sorry, picture looks different on 10.3 beta
Now, check it on your Mac. Go to FaceTime &gt; Preferences and check that it looks similar to the screenshot below:

OK. Now let's try enabling WiFi calling again. Go to Settings &gt; Phone &gt; Calls on Other Devices on you iPhone, and FaceTime &gt; Preferences on your Mac. Enable their respective allow calls options.
That should be it! Have a friend try calling you and see if a notification appears on your Mac while your phone is within its range.
If this doesn't work, comment and I'll try to help.