There is absolutely no need for RSNetworks for EtherNet.
Unlike ControlNet, EtherNet/IP is not a scheduled network, and so nothing needs to be set-up to allow the exchange of I/O data. RSNetworks for EtherNet is primarily a monitoring/troubleshooting tool.
I hesitated before originally replying, I was going to suggest you just add the 1794-AENT and the I/O modules to the I/O configuration tree online, but I am unsure whether you can do this online with CompactLogix, you certainly can with ControlLogix.
Does the system already have a lot of I/O, Produced/Consumed tags & messaging - you may be running close to the limit of the number of connections?
If this is the case, you can put your AENT in as "Rack Optimised". The AENT adapter will collate the Digital I/O automatically, and exchange this with the controller using only one connection. Any Analog modules you add to the configuration will also use a connection each, as they are not included in the Rack Optimisation schema.
One last thing, I would put the adapter in as an 8-slot chassis, even if you aren't using 8 flex I/O modules. It is easy to add more modules later if you set it up for the full complement of modules.