Just keep track of where each of the rectangles are or should be and test against those if the tilemap has a tile of the value that should collide. You can always calculate the rectangles by starting from the tile map's position and adding the x grid position by the tile width and the y grid position by the tile height (both tile sizes multiplied by the tilemap's scale). It's a little more complicated if you've rotated the map though.
Also, the tutorial is for an old version of SFML. Did you realise that? I don't think the tutorial has changed over versions but it's worth noting that you are in 2.1 version of the documentation in case you come across something that has.