"Good night, until tomorrow!"
Translation:Bonne nuit, à demain !
I wouldn't think it was specific enough. 'a plus tard' would roughly mean 'to be seen in more time' or 'later', which could be tomorrow, or later that night, or in days after tomorrow... Tomorrow is still a later time so it's not completely wrong, but still, not completely right =] Hope that helps
back translation "good night and soon" would not be right either.
à bientôt = see you soon / until soon
à demain = see you tomorrow / until tomorrow
à plus tard = see you later / until later
à cet après-midi = see you this afternoon / until this afternoon
à ce soir = see you tonight/this evening // until tonight/this evening