The manual page to which you refer concerns Corporation Tax.
If your query is in part about that, please contact the Corporation Tax helpline on 03002003410.
In respect of whether this is a benefit in kind for the employee;
Expenses and benefits: entertainment
If you already have a PSA, you should contact the Compliance Officer responsible for agreeing this with your business.
If you do not, you can apply here:
PAYE Settlement Agreements