As annoying as this is, a passing reference in a church bulletin to God as “Him/Her” does not seem to me to be something serious enough to make it worth the time and effort to approach your pastor. And, keep in mind that doing so will use up “bullets” that might better be reserved for more important battles (e.g., abuses in the liturgy, especially those that compromise a valid consecration of the Eucharist).
If I were going to address this at all (and I probably would let this go rather than address it), I would send a cheerful, helpful email to the pastor notifying him of a “proofreading error” in the current bulletin. Point out that, whoops!, God is referred to as “Him/Her,” which, “of course,” must be a copyediting mistake. “Thankfully,” you might conclude with a smiley-emoticon at the end to show you’re joking, “the error occurred here, and not where it might prove really embarrassing, as it would have done if you were inadvertently styled ‘Father/Mother’!”
The tactic is to assume that there was some mildly embarrassing mistake that occurred, rather than attribute the action to a theologically flawed ideology. And then, in the course of helpfully pointing out the proofreading error, you can humorously point to where such theologically flawed ideologies end up without ever having accused the priest of having done anything wrong.
