Janet,
Since the Thomas you have found was apparently illegitimate, he would normally appear in the indexes under his mother?s surname. However I can?t see a suitable entry, assuming he was born within the Ballymena catchment area. With illegitimate births, the father?s name box will be blank, unless he was present at the registration and acknowledged paternity.
If the McCann?s lived in Taylorstown, then they probably attended Grange Presbyterian church. It might be worth checking their baptisms for John?s birth. They are not on-line but there?s a copy in PRONI in Belfast.
I see from the 1901 census that Eliza McCann?s landlord was Wm Nesbitt. He had plot 59 in the revaluation records. He was a farmer and had some cottages on his land. His subtenants are not named, but I?d think it very likely that?s where Eliza?s house was. (That?s very near Grange Corner, between Randalstown & Portglenone. If you want to know exactly where it was, you will need a Griffiths map from Ballymena Library local studies section, as these list each individual farm, by plot number).
The John Dunseath you have found obviously lived close by, and so could be Thomas?s father but if his name and townland is not on the birth certificate or baptism record then you may struggle to prove that.
There are other McCanns in Taylorstown in the valuation records, so it?s possible that Elizabeth comes from that townland too.
How sure are you that you have found the right Thomas Dunseath? I would have expected the one in Taylorstown to be married in the 1901 census, since the date of the 1901 marriage is before census night (31st March). You?ll note that Annie is recorded as married, in Clohogue. What?s Thomas?s townland on the 1901 marriage certificate, and what?s his father?s occupation?
You don?t give Annie?s father?s name but I see a William Bruce farming nearby in the 1901 census. One of his children was named Stewart so given that was Annie?s grandmother?s name, I?d suspect these are her family. In which case, you?ll notice they were Church of Ireland. (In which case they probably attended either Duneane or Ballyscullion parish church).
http://www.census.nationalarchives.ie/pages/1901/Antrim/Toome_Upper/Clo…
Elwyn