Suggestions under £25
I'd go with something like this and stick it in a nice bottle bag.
If they are loaded you will have trouble getting them wine on a budget, so why not look for something a little different.
https://www.fortnumandmason.com/fortnums-winter-sparkling-tea-75cl
Costs £20, you can feel like it's posh enough to gift them as it's from Fortnums.
That particular one is their Christmas version so it does contain some alcohol, but they also do a sparkling tea or rose sparkling tea that contain no alcohol at all.
If you get the regular sparkling tea, you can get it with a personalised label for an extra £2 so you can put their names or a short message on the label to make it look special.
If you want/need to go cheaper for £8.50 you can get their 75cl bottle of cider.
https://www.fortnumandmason.com/fortnums-mulled-cider-with-english-cassis-2204711
I'd be really happy to get either of those as a present (even though I've already got a case of the sparkling teas as they are our Christmas day drink of choice).
They also have 50cl bottles of Chocolate Chestnut Liqueur, Figgy Pudding Liqueur for about £25 each if you want to spend a little more, but they are smaller bottles.
edited to add
If the third one is a child, I'd get some of their Christmas coal (honeycomb covered in chocolate and black sherbet).