It seems like texture.updateSamplingMode() doesn't actually work (though looking through the code, it looks like it should, as it's making the right gl calls).
http://www.babylonjs-playground.com/#Q9RDM0
I noticed this as loading a .babylon file with sampling mode set wasn't working (though the samplingMode property on the texture would be correct, it was not rendering in that mode).
(And assuming that it should work, https://doc.babylonjs.com/resources/file_format_map_(.babylon)#textures should probably be updated to include the samplingMode property)