They are trying to paint him as a hypocrite and as doing something morally wrong, because he is a Labour man and dared to order quality wine to entertain guests with. I think that they would have done no different.
As far as I understand it, the use of his company is also not illegal.
Think about it, if any of it was illegal, then we would be sure to hear about it, as his enemies would make sure of it.
My impression is that this is an attempt to smear him. It is the usual spin again.