Damn, wonder what the issue is. Internet here fine - might try another PS4 game.
Solved - normally when a game needs an update it is kicked off when you launch the pre-update game. In this case this did not happen even though I tried launching the game it reported network not available and did not start the download. Tried this a few times but no luck. Then clicked options from the game tile from the PS4 home page which gave me the option to check for updates which then launched the download. Very odd as have loads of games and have not need to get the update to download this way before. Not even GT Sport come to think about it as all previous updates have been kicked off by starting the game. Very odd.