Is it posible to have a blutoooth system to match with my phone to power only saddlebag speakers? How much power is necessary that I could hear them without anything on my handebars?

 

Yes it is, here is a bike I did the paint and bodywork on that has JL Bluetooth HU in the bag with JL amp and JL speaks in the lids and highway bar pods. I fixed his dash to hold his Iphone which is wired into the HU USB.

 

100% fully possible, you need quite a few speakers in the back and a boat load of power. There's tons of bluetooth modules out there.

Here's a simple install we did.