After running a sample demo, example, NLCD, I was unable to get the xyz tile server to be exposed thru the VM running GPS through to my local machine.
@echeipesh came up with a nice work around:
Expose a specific port link during the docker run initialization command, as per:
docker run -it --rm --name geopyspark \\n -p 8000:8000 -p 4040:4040 -p 7070:7070 \\n -v $HOME/.aws:/home/hadoop/.aws:ro \\n quay.io/geodocker/jupyter-geopyspark
And then include the 7070 port ID in the calls as per:

Not sure if there is permanent solution for Macs. (This is apparently not an issue for linux machines) But this works for now I suppose.