Where a wedding takes place in an unlicensed venue and the client pays for all the alcohol (i.e. there’s a free bar and wine on the tables during the meal), no alcohol licence is required. No retail sale has taken place and the alcohol is truly free to the end consumers, so it cannot be licensable.
If you supply alcohol as part of an offer you would need a licence (rather than the village hall), whether there was a separate charge for alcohol and food or not. For example, the ticket states that the buffet costs £9.99 with a complimentary glass of wine included. In this situation you would need a personal licence because in reality you are supplying alcohol as part of the cost. The same would apply if the tickets were available for £8 without alcohol but £11 with one glass of wine included.
The village hall would not necessarily need to be licensed as you would get a TEN for the one-off event. In a situation like this, it would be wise to check with the venue whether you are expected to take responsibility for any alcohol supply under the terms of hire, or whether they have a premises licence you could trade under.
Scenario #5: You run a prosecco van and are set to trade at a festival.
In this situation you would undoubtedly be making a retail sale as you would take money from the end customer for each glass of drink provided. Therefore you would definitely need to have a personal licence and a TEN or premises licence would need to be in place for the festival site.