I love these kind of shots...night time...long exposure. Great job and nice composition. However, there does seem to be a lot of dead space in the uninteresting sky.
Composition seems forced - why have the fountain so close to the column, and yet have so much remaining space either side? If you'd separated them so that they were placed more independently in frame you'd surely have a more satisfying image, no? I'm not aware of anything that would be more distracting than your current background if you did that ... Nicely done exposure wise though, but that isn't enough to overcome the compositional problem.