its up to the phone how much amplification there is on the analog output. the latest BT specification is pretty low power, but which is lowest will depend. in my own experience, it seems like i get longer battery when using the jack over the BT radio, but i have not tested this rigorously

https://www.quora.com/How-much-power-current-goes-through-an...

https://en.wikipedia.org/wiki/Line_level

https://www.turntablelab.com/pages/headphone-buying-guide-wh...