It is a long time since we did a Thomson, try a few of the reviews they may have some more upto date info.
There were house brands of all the main spirits and a topshelf was 70p extra.
IIRC there are a draft bitter and larger, house wine by the glass basic cocktails and a variety of other drinks as well as the gin.vodka,whiskey,brandy options.
Also there was a coffee of the day but again you could make your own with a shot of the included stuff.
What we did was check the ingredience of the "premium" cocktail you could sometime make them from the included options anyway.
EDIT: duh should have checked the following posts.