There are a few residences starting Penrhiw.. in the area,but no ending like ..bela,and there is a "cwrt y bela",which seems too different iniitially,even allowing for mistranscription.In looking to see if there was an English equivalent,I found that "bela" means "pine marten"-very apt as they are difficult to find!
I can find a Penrhiwbaili,but that's in Carmarthen.
Regards
Roger