@Anonymous User Did you ever get anywhere with this?
I only ask cause we've got the exact same problem. I was given two 3 month vouchers for Hayu and so we thought we'd try it.
My partner's Now TV account is the one we use in our house, but he has had a very long Vodafone voucher for his Entertainment Pass (expires end of next year), and my guess is that his Vodafone voucher is stopping Hayu from being added. It's not there as an option in 'passes and vouchers' and if he tries to play something on Hayu he just gets endless error messages about how the purchase couldn't be completed.
From my rough knowledge of how badly put together systems work (which in my experience often applies to Now TV), if they've 'refreshed' accounts to allow Hayu as a pass, it appears they can't edit accounts that have Vodafone vouchers on them. Probably because doing so would cancel out the management that Vodafone does of the account to give you the Entertainment pass. So we're probably going to have to wait until his Vodafone offer expires before we see Hayu as an option.
We emailed Now TV (using the link @schnapps provided) to ask and they was all "we're trying our very best to bring Hayu to a small number of limited accounts which do not yet have access to it".
I expect this to be fixed as quickly as an updated Now TV Apple TV app.
In the meantime, I've ended up using my old and disused Now TV account from years ago to use the Hayu pass, with just a spare Chromecast into the TV. Not ideal, but it works.
