I may be wrong here, but wouldn't reception be pretty poor using an antenna designed for >10x the frequency of FM radio? There's a reason why most FM radios have protruding antennas - the wavelength is ~3 meters.
Normally they use the headphone cable as an antenna (which leads to contortions if you want to listen using bluetooth, since with most phones the software assumes "oh, headphones plugged in, audio to headphones it is")
Windows Phone did a good job with this; the music app let you choose to override the default and play through the output device of your choice.
My first Android smartphone had an FM radio, and it used the headphone cable as an antenna. You had to have headphones plugged in or you got nothing but static.
The reception is crap, but the S/N ratio is still good because the electronics add minimal noise, so most of the noise is atmospheric interference which is also reduced.