What you do you hope to get by connecting a Bluetooth speaker to a soundbar? Are you trying to get sound from both of them simultaneously? Because that’s about all you’ll accomplish. But if that’s the goal – yes, the Sony’s RCA outputs can connect to an AUX input on the soundbar.
As far as the wireless surround sound, that would only work if the soundbar came with its own wireless surround sound speakers. Wireless systems like this never permit using the speakers of your choice.
Regards,
Wayne A. Pflughaupt