The A466 has a good bus service to Monmouth and Hereford.
Palace Farm is 0.6 miles walk from the Bus Stop which is situated just at the end of the lane.
The number 36 services this route. The bus route can be found on this link
From Hereford bus station you can can catch the X3 to Abergavenny
/ T14 to Hay-on-Wye or the Number 34 to Rodd-on-wye
You can plan your journey on the StageCoach website