A system may incorporate up to 256 V-Page or V-Com stations by simply connecting them to PoE enabled network switches and routing their Dante or AES67 audio signals to the Q-Sys core.
The only other limiting factor would be what type of QSYS Core you are using. For example, the Core 110f would limit you to 128 stations in that specific case. For a technical note on QSYS Core limitations, see the attached document.
From a networking standpoint, it's also important to remember that each VPage or VCom units has both a Control IP address, and an Audio IP address. You need to make sure that your network is large enough to handle these properly.