I’m not sure I agree there - the Small Wonders section of the fine wine list defines them as ‘showstopping wines for £20 or less’. I’d argue that by definition these are amongst the best value wines in the range.
The bigger point here is probably about what this list actually represents, which is a marketing offer to highlight a group of wines that the buyers believe delivers value at their relative price points. Up front, the offer has the word ‘value’ writ large, and that’s a word with connotations around lower prices. Tesco didn’t name their budget range ‘value’ for nothing. If a promotion is all about value then by its nature it wouldn’t include pricey premium wines, even if it’s a Bordeaux chateau producing a product comparable to a first growth at £95 a bottle. If you could quantify enjoyment per pound spent, maybe that wine would find its way into a top QPR list, but not one with Value as its key word.
To your point, I think it would be interesting to see an offer that was broader in terms of highlighting wines in the range that the buyers believe deliver a superior experience to their relative price point, and covered a wider price range. To some extent I suppose the Wine Champions offerings do that, although not quite so explicitly. However, it almost certainly makes sense with an offer like this to have the wines all fit within a relatively narrow price range because it makes it easier to digest for your more casual customer. This is just my personal thought on it, but I tend to find offers like this one are really about highlighting some of the less explored corners of the range for members who, unlike lots of us on here, might not naturally try. And if that’s what the offer is looking to achieve, then it’s best to include wines that are affordable to all, where the consumer will be more likely to take a punt.