The Marantz is an excellent sounding older surround receiver but it has no purpose unless you have different speakers connected to it and the Samsung.
If you do then you can connect all your sources to the TV. Use the ARC (audio return channel) HDMI input on the TV to connect the HTiB and turn the ARC on in the TV menu.
Connect the TV optical audio out to the Marantz receiver.
Turn on the one you want to use.
If your plan was to use the Samsung speakers on the Marantz receiver you could do that but you would need a self powered subwoofer rather than the passive one that came with the HTiB. Connect the Marantz to the TV the same way.
Modern entertainment gears want a receiver with HDMI switching, so all your source components hooks up to the receiver, then a single HDMI cable receiver to TV, and your receiver driving all speakers.
Anything else and you are just jury-rigging stuff with spotty levels or satisfaction.
Maybe it's time to upgrade that receiver.
Hmm... ok. I'll probably sell it then. If you believe I should upgrade, what kind of receiver should I upgrade to? What would work best for all of the sources I described in my original question where I can hear surround sound on all devices?