There are quite a few posts on this forum querying whether VFTV can be cast to Chromecast. None of these that I can see have had any response (which is disappointing). As far as I can see, the VFTV app will not work if casting or screen mirroring is enabled, and there is no Cast icon within the app -- so I am guessing the answer is that it is not allowed ... it would be good to hear this from somebody in Vodafone who knows the facts.
What I am wanting to be able to do in particular is cast the Sky sport channels. I travel a bit, and it is great to take a chromecast with me to plug into whatever TV I have whereever I am to keep up with the sport. Sky Go let's me cast the sports channels, but I am keen to cancel my standard Sky account and subscribe to Sky sport through VFTV. It just appears that I will lose some functionality if I do that.