If you look at the Metro Gold Card issue, AFAICS it’s an add on to the ENCTS card, and normally such add ons are done at county level. But for vast areas of Northumberland the facility is not going to be much use at all, so how does Northumberland justify paying for free Metro/Rail travel for just a small fraction of their residents out of council tax? Seems to me for the former Tyne and Wear authorities it’s a different scenario, a much higher proportion of their residents can benefit.
(I’m assuming here that the £12 fee is little more than an admin fee, the actual travel costs must come from council tax.)