The bank interest rate in Spain across the last decade or so has averaged 2.5%. Real Madrid, as a secure company that always paid back its loans, got loans at not much above rate (but yes, they did pay above the base rate).
You could argue that other European teams are not considered as safe corporate risks and therefore pay higher interest rates which is in some way unfair. However there is no taxpayer subsidy, hidden or otherwise, in a business taking out a business loan and paying it back at a normal commercial interest rate.
Incidentally last year they had brought bank borrowing down to 146m Euros and had 98m cash in hand. Net borrowing about 50m - so even with interest rate rises (like took place in Spain last year) they aren't paying out much. Their business model works fine, at least in the short-term. It's their sporting model that doesn't work as well as they'd like.
Yea but the bank that loaned madrid all the money at favorable rates, was the same bank that needed saving by the European Union. Which is taxpayer money, because if a bank gets government support, that really means taxpayer money !