It's not something that is commonly said, no. Of course, it is perfectly understandable, and I suppose that a man might say it to a woman he likes, but it would be helpful to know the exact situation you are talking about. What is the relationship between the man and woman, how are they communicating, and what is the man trying to convey? (That is, is he trying to be romantic or just neutral?)I know that おやすみなさい。良い夢を❣ means "goodnight. sweet dreams!"
I also know that 良い夢を is not something regularly used in Japanese. Right?