I managed to bash the script into using my hosted feature service, along with referring to a traditional tiled service.
This can be seen here. This is not using the Esri leaflet library.
However, to match some of the other maps on my page, I need to include the Esri leaflet library so that I can incorporate the Esri dark blue vector tile service.
As soon as I switch from using leaflet-0.5 to the email@example.com (from the vector sample) in the header, along with the latest CSS then I get the following error in the console
leaflet.js:5 Uncaught Error: The provided object is not a Layer.
at e.addLayer (leaflet.js:5)
at e.addTo (leaflet.points-layer.js:44)
at Object.<anonymous> (d3.v3.js:1996)
at Object.event (d3.v3.js:504)
at XMLHttpRequest.respond (d3.v3.js:1949)
Would love some help getting this resolved. I did try to replicate my sample in a JSFiddle, but could not get it to run.