if you can demonstrate that it is hospitality (you wouldn't use the term entertainment) and forms part of business development then you can justify it.
this may require you to have a very clearly defined business development, marketing and company expense policy which works both ways as it; enables you to undertake such activities but also sets out a prescriptive approach which of course limits some good old ad-hoc pub time with your colleagues. for example you could pre allocate £2k in your annual budgets and business plan for hospitality and business development, it would be poor performance not to meet your own kPIs
Hospitality still sounds like business entertaining to me...