Iphone and Android should play pretty well via Bluetooth. It has come a long way. There is going to be a few factors. The source you are playing. I use spotify, and I have extreme quality as my setting for streaming and downloading music. If you have a sound quality option in the app your using, make sure to use the highest setting. Also keep in mind when you play music, there is a DAC or digital to analog converter, and the quality of DAC has a lot to do with the sound quality. Unfortunately, you can't really change the DAC. There are external DAC's, but it's not exactly the most convenient option. If you play via Bluetooth, your using the DAC in your phone. Via auxiliary plug, you use the DAC in the head unit. I dont think center point has anything to do with boominess. Has everything to do with sound stage and imaging. Buuuut... the audio pilot setting could make audio more boomy. While I like the idea of audio pilot technology, it's not good for audio from a sound quality point of view. It's going to raise certain frequencies to compensate for the level or road, background and ambient noises in the vehicle. This could absolutely make audio sound more boomy. If audio pilot is on, try turning it off.
Edit: bluetooth streaming = head unit DAC, auxiliary plug = phone DAC, then possibly headunit DAC as well.
I've heard audio over usb is the best option. But I've never accomplished this with android. I think iPhone is capable of this