No line-up at ME. You can specify that you want a female (or male) therapist but you can't pick the woman. Maybe be a cute college student looking for some $$$ or may be a granny that rests her gut on your head while she massages your shoulders. It's Russian roulette.
Now once you find someone you like, you can definitely make appointments with that person. I was lucky enough to land on a young cutie on my first time who gave one of the best massages I've ever had. She left after a year and went to work at a high end spa. When I found out she was leaving I would spot another cute therapist in the lobby and ask the receptionist "what's her name again?" and then book with that girl next.