Not without some kind of step-down converter. The Amp’s speaker level outputs would be much too strong to feed wired headphones or a Bluetooth transmitter directly. In any case you presumably wouldn’t want to listen to the main speakers at the same time so in addition to a step-down you’d need some kind of speaker switch. All rather messy,
If you only wanted to listen to the turntable on the headphones it would be straightforward to put a Y-splitter cable in the line between the TT and the Amp. This could feed either a BT transmitter or a small headphone amp.
If you wanted to play any music streamed to your Sonos through the headphones the best solution would be a Port (+ a BT transmitter or a headphone amp).