Social care - who should pay?

What's the rules on drinking in these care homes.

When my Dad went into residential care we were told that if had been in the habit of having a drink he would be able to continue. But he was past enjoying a pint.

My mother liked a glass of sherry - had in fact been hitting the bottle quite hard before going into her care home - but largely because she couldn't remember that she'd only just had one! My brother, who did much of her shopping, had begun to water it down a bit.
Care home staff kept a bottle of her favourite and for some time would give her a glass every day. There came a point where she no longer wanted it, though.