SQL prompt doesn't offer a single quote column aliases (which is fine). The code analysis feature says :

"If aliases are standard identifiers, they do not need delimiters. If they are not, then they should be delimited by double-quotes, not single-quotes."

what would be good is if SQL prompt had an option within SSMS to highlight double quoted column aliases in another colour (purple perhaps) just to make code more readable... sometimes the sea of black is hard to read when you have long, complex case statements etc.