I would totally bring it to their attention. They may not be bored, there may be something else going on, but the only way to know that is to ask.

(For most Ts. From what you've said about this T in other posts, I'd just look for someone else!)

My ex-T once seemed bored when I was talking to him, very early on. Without thinking, I said something like, "Oh sorry! Is this boring?"

He said, "What? No! Bored is the last thing I feel!"

Then... and this is one of my absolutely favorite memories of him... he completely rearranged his face to try to look intensely interested in what I was saying! It was so funny, it really surprised me - but I realized he was trying to convey what he was feeling, so I didn't say anything about it. But that face rearranging... I still remember the expression, and I really appreciated it!

So, in most cases (though maybe not your current T) you should ask - because you just don't know what's actually going on in their heads!