If you're refusing to date someone solely because they're trans, then yeah it kinda is. Things like genital preference, the person "passing", etc are preferences you're certainly allowed to have, but are going to apply on a case by case basis. If you're otherwise attracted to someone and the only deal breaker is the fact that they're trans, that's by definition a prejudice against trans people.
Edit: listen nobody is forcing yall to date a trans person. What I'm saying is that most valid hang ups someone might have don't apply to every trans person, there's gonna be trans people with the junk/body type/voice/whatever else that you're into. So refusing to date someone just because they're trans is the prejudiced part, not whatever personal preference you have that's gonna stop you from dating some or most trans folks.
The terms broadly overlap, but the distinction matters to some people and that's okay.