I'm looking for a william demaine born 1679 in pateley bridge
And a warm welcome to Rootschat from me.

Could you let us know where the information about the birthplace and year comes from? (Is it a transcript, an online tree, a deduction based on other sources?)
As arthurk says, there are several Demaines (with spelling variants) in the Skipton area (based on transcriptions on FreeREG) around the mid 1600s, but I haven't spotted a baptism for William c1679 yet - although not all parish registers have been transcribed.
Depending on when the children were baptised, there is a possible marriage (on FreeREG) 27 Sep 1715 Fewston (which is near Harrogate, about 10 miles from Pately Bridge) - William DEMAYNE and Margat BUTTERY. (This might be the same person as William DUMAINE, son of John, baptised 19 Nov 1693 in Fewston).
No definitive solutions yet, but Rootschatters are on the case!
Philip
(p.s. - if you could cite sources for your information it would be very helpful - as you have traced the line back well over 300 years you probably already know that parish registers are far more reliable than some online trees!)