The choices are pretty simple.
Pandora -> JRiver WDM Driver -> JRiver MC -> ASIO ravenna drivers -> Merging Technologies Anubis audio device
or
Pandora -> ASIO bridge virtual cable -> ASIO ravenna drivers -> Merging Technologies Anubis audio device
If Pandora can output in WASAPI Exclusive Mode, then the JRiver WDM Driver will take what it is given.
If Pandora can only output in Shared Mode, then you need to set the format you want in the WDM Driver, and that will be input to MC. In Shared Mode Windows Audio will get involved in the 'Pandora -> JRiver WDM Driver" part of the Audio Path, and will remix to the format specified in the WDM Driver as required.
https://wiki.jriver.com/index.php/WDM_DriverI believe you could also use;
Pandora -> WASAPI Loopback -> JRiver MC -> ASIO ravenna drivers -> Merging Technologies Anubis audio device
You might also be able to use;
Pandora -> ASIO bridge virtual cable -> JRiver ASIO Line-in -> JRiver MC -> ASIO ravenna drivers -> Merging Technologies Anubis audio device
But you would still need to configure the ASIO Line-in audio format, it is an extra step in the Audio Path, it might only work with a physical Line-in, and I don't see the point really.
Those are available in the "File > Open Live" top menu. I haven't used either, so can't help further on that.