Yes you can! You can publish your own hosted elevation and hosted tile layer in ArcGIS Online.
For the Tile Layer you want to use as a basemap
You will want to create a tiling scheme for your data which matches the same projected coordinate system you used in your scene layer and publish the tile layer. You could create a tile package and upload that to ArcGIS Online to create a hosted tile layer and then you can use "Open in Scene Viewer" which will open the data in a local scene using that tile layer and you can then add in your scene layer
For the Elevation Layer in your local scene
You will want to use the same tiling scheme but you will need to use a different tiling scheme file. The reason why you will want another tiling scheme file is to define the tile format as LERC. if you do not do this you will end up with another tile layer instead of an elevation layer. Once you have the tiling scheme file ready you can use the Manage Tile Cache tool and then Export Tile Cache tool to generate the tile package which you will upload to AGOL and create a hosted elevation layer.
Creating and Using Elevation Layers in ArcGIS Online & ArcGIS Pro | ArcGIS Blog
You can then author the local scene in Pro which can use all the services you published or you can author the local scene in the scene viewer.
How to Create Local Scenes in the Scene Viewer | ArcGIS Blog
Cheers
Russ
