Flown my Phantom 4 drone on 9/2/2016 in 20 lakes basin and had 50% battery charge. Panned out as far as 352meters to capture the mountains. My battery went to 31% I pressed the Return To Home feature and it was starting to come back to me slowly then it stopped and went back. I tried manually to get it back to me and it slowly worked so I decided to press RTH again. By this time the battery dipped to 28% and I tried again to RTH and it had trouble coming back to me.

Sounds like you are too reliant on Return-to-Home function.  Also sounds like you are not that familiar with your User's manual.  And, you might consider not pushing your limits on how far you fly on low available.  If you tried manually to get it back and it was working, albeit slowly, why press RTH again.  RTH won't make it come back any faster.

RTH is a slow driver and will cruise along at a lazy 10 m/sec (in still air).
You can drive at a snappy 16 m/s.
There's nothing to stop you from pushing the right stick in RTH to give it a kick along rather than watching it go nowhere in a headwind.