I am not able to get points of interests of type wind turbine and container gantry crane to show up on the zoom levels that I tested (15-18). Since these are rather large structures I think it would be nice to include them in vector tiles.

Example of vector tile where I would like the cranes to show up: https://tile.mapzen.com/mapzen/vector/v1/all/17/103341/65074.json which is the vector tile for this location: http://www.openstreetmap.org/edit#map=17/1.26857/103.83637