Hi Rex, we deal with a lot of live streamed events. Typically I'd always use Ethernet connectivity, however if we need to use Wifi I have found it more beneficial to run access points running unleashed and broadcasting 5GHz only (If the streaming device allows 5GHz) on a separate dedicated LAN and rate limit as Mike states above, although this only rates at host level and not at network level. If you need the controllers however you can also force the Wi-Fi traffic to route via the ZD controller. We've run multi bit streams (480, 576 & 720p) on this setup and it's worked fine. Final thought is that you could also limit the volume of clients connecting to these two access points which would force hosts to connect to other access points...
Hope this helps
Chris