Neither seem to be working in EEVEE but it does work when I switch to Cycles in 2.8. Blender 2.8 is in ALPHA so I thought it would be working by now.
The only status when you should expect something to work is official release. An in-between build can have any feature broken at any moment.
Bump should have an effect. There was a thread, here, about a broken antialiasing for image textures using it. So, if it does not work anymore; it worked previously.
It will probably fixed before official 2.80.
But don’t expect displacement for EEVEE coming up in few days. It always was a target far away in to do list. ( I mean it could be a target for 2.87,2.88,2.89,2.90…) We don’t know.
Currently, 2.8 alpha does not have a working sculpt mode. All opensubdiv stuff relative to multiresolution modifier will be fixed before an hypothetical displacement in viewport.
Even in Cycles, displacement had an experimental status in 2.79b official release.
Having this feature more stabilized will already be a new feature of 2.80.
I tried a 16-bit png as bump map and that works. I was using a 16 bit tiff (which works on 2.79).