Here is the latest guidance from Visit Wales and as you can see it is not good for B&Bs, Hotels, etc.
Honouring bookings and advertising availability
To help further clarify, no bookings can lawfully be honoured in respect of ‘stays’ during any restricted period, which is currently up to 18 June 2020 unless you are requested to re-open by the Local Authority or Welsh ministers for specific purposes only.
As a reminder, businesses should also not be advertising availability during a restricted period. If you advertise via third party websites or the Online Travel Agencies, please take some time to review your entries on these sites and amend your availability accordingly.
You are able to accept bookings or reschedule bookings that fall outside this restricted period, however, there is a risk the restrictions will remain in place once the rescheduled date comes round and therefore any bookings will be at your and your customer’s risk so you will need to make this clear when entering into any contractual arrangements.