For simple antennas, I suspect you are correct.
However, I think it when more complex antennas with complex radiation
patterns that fractal design becomes useful.
You find this type of antenna used at microwave frequencies, which was why
I suggested you try the microwave groups. In one of those you may well find
someone who has designed a fractal antenna.
Microwaves and HF:
http://www.youtube.com/watch?v=3Xq6h31UCKQ [starting at time 1:10]
ham antennas too, apparently.