In the geoviews guide for Bokeh, it states that Bokeh only supports Mercator projection, and yet most of the example projections use PlateCarree, and then the output looks like Mercator.
Does anyone have an idea of what is going on with the projection and the output of the figure?
GeoViews elements can handle data in any source coordinate system. When plotting GeoViews elements with the bokeh backend the data will however automatically be projected to Mercator coordinates since that's the coordinate system used by the tile sources. In other words, you can input data in any coordinate system, but when you plot with the bokeh backend it will project the data to Mercator for display. When you plot the data with matplotlib on the other hand you can define a custom target projection.