As jamjar stated the Marriage was at the Parish Church, Keith, Banffshire
William of Glass Parish, Ann of Keith Parish
A William MAN married Jean STRONACH 3 Jan 1769 same Church
William may have been Bapt same Church 25 Dec 1737 to GEORGE/MARGARET nee MALCOLM
There is a ANNA Man Bapt 3 May 1735 Parish Church, Botriphnie, Banffshire, to GEORGE/MARGRAT nee MALCOLM
So this may be your Anns Baptism.
All above on FreeREG
This looks like your William;
WILLIAM Stronach christened 05 Jul 1748, Glass, Aberdeen to THOMAS Stronach and Margt BREMMER
Siblings;
ALEXR 11 December 1744
JOHN 10 May 1759
(large gap, children born elsewhere?)
Source Familysearch.Org
Although it would make Ann 31 at Marriage in 1766 and William only 18.
Only ones I can find though.