They could be, but I don't think you can really tell.
There are other examples of William Bouch in Cumberland at that time:
one, son of Martin, christened 24 Apr 1773 at St James, Whitehaven (a bit further from Cockermouth than Wigton is, and in a different direction;
another, son of Lancelot, christened 6 Mar 1779 at Brigham, just outside Cockermouth.
Also an older one, b abt 1756 who married Elisabeth Langcake on 9 Sep 1779 in Wigton
and a younger one, son of John Bouch & Ann Ralton, christened 12 Jun 1805 at Allhallows, halfway between Wigton & Cockermouth.
All this from IGI. So clearly several families, may well have been related, but nothing I can see to tie down which William is yours.