Light in minecraft is pretty limited. In fact, a light source don't really produce light, it just brighten the cubes around it. So, a torch on top of a pillar, seen from far away, will just be a white pixel in the sky, not much different from a star.
The best way to see something from far, so, is not to make is bright, it is to make it large and recognizable, something that will not confound itself with the background. Making a huge ball of glass filled with lava, for example, is a good way to mark a place. But so is a sphere of red wool covered in torches and a large cube of glowstone. The difference is brightness from torches vs. lava is negligible for something like this. For afar, most details will not be visible, but it will still catch the eye as something very different and not natural.
So, in short, to mark a place, make something big and recognizable, not a small, bright light.