geek4me: Thanks sbiddle, it sounds to me that trying to get a VPN router with a Voip phone running behind it is not a good idea. I think I'll look at other ways of getting the LG Smart TV to access a VPN as I don't want to lose quality on the phone line. Appreciate you helpful comments.
In which case you would simply dedicate a port of the Mikrotik solely for the TV which could maintain a 24/7 VPN connection to the US, while other ports would access the internet as usual via NZ.
The problem is when you start trying to create complex setups like this that my comment about RouterOS applies - the web GUI is fine for basic setup, but you really do need to have a good understanding of networking to start fiddling under the hood. I don't know what your level of knowledge is, so it could end up being a frustrating product!