Is it true that a husband is not permitted to surprise his wife if he has been traveling, and does this ruling apply to the wife as well?

The prohibition against a man approaching his family at night is authentic, and it applies specifically to one who has been absent for a long time and whose family is unaware of his return. As for one whose absence was brief, or whose family knows of his arrival, the prohibition does not apply to him, because the underlying reason (illah) is absent. The underlying reason is the fear that a man might find his family unprepared, which could lead to aversion, or that his arrival at night might cause him to suspect his family. The prohibition is directed at the husband, and it also includes the wife due to the shared meaning. This etiquette should also be observed with those who are not spouses.