You can have more than one bus per process (each tied to itsown queue), in fact it's the recommended way to ensure the queue is not monopolized by one consumer's message types.
Configuring the bus with DI in that case might be tricky, as you have to explicitly specify the bindings between bus instances and the consumers each one serves.
It might be easier to split them into separate applications/services, but I know it can be a hassle to deploy and configure.
"queue for publishing" doesn't make sense though. Like Travis said, post the details to the group, you'll get a lot of help there.