The singers/folk scene in North Wales has never been very prolific.
Certainly those that have been mentioned, also there used to be an Irish come singers session in the kings Arms in Holyhead. Unfortunately the pub is now closed. However the band of us (Traedmoch) that started it all is still going! And they will probably be able to give you some info on what is happening around the bazaars.
Their website is at the following:
Good luck and if you speak to Frank, tell him Chris sends his regards.