The axis of the coil is vertical, and one pin is at the clockwise end and the other at he anticlockwise end. The dot marks one of those. (I don't know which one)
The pin dot is needed because some of the magnetic field will come out of the coil. This will interact with other components, specifically other inductors, but the PCB and any box may have an effect as well.
That inductor is encapsulated, but on open inductors it's quite easy to add extra turns for auxiliary outputs. Fig 13 of **broken link removed** shows an application and it's important to wind the extra turns the right way round, and for that the dot is really useful.
It's a bit like the polarisation of transformers or speakers, in that you only need to worry about them when other transformers or speakers are connected.