I don’t know if there are Wallaces there today. I’d suggest you write to the church to see if there are any in his congregation. Rev DC Christie, St Colmanell’s church 42 Church St, Ahoghill, Co Antrim BT42 2PA. Alternatively they have a Facebook page:
https://www.facebook.com/StColmanellsAndPortglenoneChurchOfIreland
I found your Wallace family in the 1911 census:
http://www.census.nationalarchives.ie/pages/1911/Antrim/Ahoghill/Ahoghill_Town/115425/
Martha Wallace (nee Hamilton) died 2.4.1917 at Killane (a townland near Ahoghill). Her sister Lizzie Anne was the informant. Martha’s 7 weeks old son Hugh died a few days later on 10.4.1917. Lizzie was also the informant.
I don’t know what happened to them after that as there are not really any more recent records to consult.
There are 2 Wallace gravestones in St Colmanell’s graveyard. Neither has any specific names engraved on it so can’t tell you if either is your family.