Hi Allan.
Thanks for your mail.
Having had another look through records I see that a Richard Rowland, (Born 1802/3 at Amlwch) married Catherine Parry at Amlwch in December, 1830. If this is your Richard then their son, Richard, Born in 1827, would be shown as illegitimate.
Nothing, other than that he was employed for a time as a clerk at Llwydiarth Esgob, connects him to the Prichard family.
Owen Rowland, one of the bond holders,(timber merchant), was probably Richard Snr's father and John Prichard, (farmer) of Llechog, some other family friend or relative.
The illegitimate child could have been the cause of Richard Snr's break with Llwydiarth Esgob but we'll never know for sure.
Regards from Peter.