First of all keep in mind I am far from expert on this. However, I have a similar arrangement, a Helix 10 at console and a Humminbird 898 at bow. The difference is the Helix has a transducer but I don't have one for the 898. Therefore, I networked them so I could keep track of conditions while fishing at bow looking at the 898 which is getting its info from the Helix (Note: I learned that you have to turn the Helix CHIRP feature off to make things work). In your case each unit has it's own transducer so I see no need to network them. I hope others chime in on this topic as I may be missing something and I certainly don't want to impart wrong information.
GET THE NET HAROLD, GET THE NET!!