I remember reading "Worf's First Adventure" in the fifth grade (1993-94). Little did I know I had to present it in front of the class. Needless to say, fifth grade wasn't a very good year for me (Trek didn't exactly help my popularity)
That makes me feel old. When PAD's "Worf" trilogy came out, I bought them for the school library in which I worked. They didn't get borrowed too often, but TNG was released first on VHS sell-thru, and it was shunted to late night viewings when it did get to free-to-air TV.
But there were plenty of Year 5 and 6 kids who came in to talk about cool SF TV shows, although it was reruns of TOS in the 80s, in my previous school, that had more kids excited about ST.
And, you know, if you're going to get bullied, the bullies will pick on any aspect they can that gets a reaction. A liking for ST or SF or reading is not why they're bullying. It could also be hair colour, speech impediment, too much spending money, not enough spending money, having one parent, having both parents, owning the wrong colour backpack, a big nose, a stutter...
I'm betting you got teased because you actually had read a book, as requested, and thus could do an impromptu book report. The bullies probably hadn't read a book since Year 2.