Could you do a reading on a public figure you disliked in a unbiased way?
Yes, if they asked me to. After all, like the non-famous ones, they're just human beings struggling to get through life the only way they know how. Fame doesn't mean a lot to me, anyway. One particularly obnoxious guy tried to pick me up once, and when I ignored him, he tried again by telling me that I wouldn't reject him if I knew his TV show. Oh, yes, I bloody-well would. I'm interested in character, not in TV-minutes or magazine-inches. And all clients are just clients, no matter their manner, or even their smell. I put aside my own impressions and let my deck tell me what their life feels like to them, and what they need to do to improve it.
And if these Famous People don't ask me to read for them why would I be any more likely to read for them than for any of the other billions of humans on the planet?
Actually, when I saw the thread title (Reader Bias), I thought it was going to go in a more interesting (for me) direction: the unconscious biases we show in how we interpret stuff.
For example, we might have a client sitting in front of us in a dodgy relationship, and they might ask us what can they do to improve it. They might pull the Death card. To the fluffier among us, that might mean that the relationship will "transform" into something better with that same person, while the Tarot deck might have actually been trying to say: this relationship is unsaveable, cut it off permanently right now, grieve, then go looking for someone better.
That's the kind of bias I'd hoped the discussion might be about.