I found this post in the NOW TV community in which a member from the NOW TV team has responded. It is seen that they don't support VPN and this is due to their license agreement. Please have a look.
Thank you for answering.
The link is from 2014 but I have been using NowTV with VPN for years already
Apple TV4 still works with an UK ip address but MacOS and Freedome does not work as NowTV can "see" that I do not come from the UK.
So something has happend, either with Freedome or NowTV.This is a shame as Freedome works in certain territories perfectly.
The post is pretty recent, it was replied on 29.11.2016 by the NowTV team member. May be they are catching up with Freedome IP addresses in the recent times.