In my opinion the most SPA orientated location is at Hotel Špik. But for the kids, who prefere pools, all locations are good.
(phone numbers are on the links). I can call the centers for you… just call me! ;)
https://hotelspik.com/en/wellness
https://www.hit-alpinea.si/en/wellness/wellness-larix/
https://www.hit-alpinea.si/en/wellness/the-relaxation-centre-at-the-kompas-hotel/ (i think this one is smaller)