Hi voelk01,
Welcome to the community.
Yes Enterprise plus licensing limits you to add just three hosts to vCenter server. But if you are buying a Horizon view bundle you will also get a vCenter standard desktop license.
FAQ says this
Q. I have spare vSphere Enterprise Plus licenses. Can I use them for desktop virtualization?
A. Yes, customers with spare vSphere licenses from past purchases can use it to host a VDI environment.
Desktop licenses covered by this provision, however, may not be managed by the same instance of vCenter which is being used to manage non-desktop OS virtual machines.
So you may need to deploy another vCenter to manage the two new hosts.
The best thing to do would be to write/talk to VMware regarding this. They will clarify all your doubts regarding the licensing.