Earned First Professional Feather, Now What?

Any writing and publication credentials can be used to establish yourself as a legit writer. The fact that the anthology is published by Simon & Shuster should help you.

Cool! Congrats. Be sure to mention it in your query letters.

Congratulations on placing your story. I agree that mentioning it in your query letters makes sense, but really only if you are marketing a science fiction novel. I disagree that S&S will care that you have a short story in a Pocket anthology. To the editors who don't work on Star Trek, the imprint might as well be at Random House. Also, keep in mind that every single SF editor (at least all I've worked with) in NYC pretty much feels that selling well in Star Trek is a credit to the selling power of the Star Trek brand and not to the individual authors.