Has Chase started charging booking fees?

The other night I made a hotel reservation. I had some questions so called in. The agent quoted me a price, charged my card, that was that.

The next day I took a look at my confirmation email, and I saw something that puzzled me greatly. At the bottom, there's a line that says "Total," which gives a price of $X. Then below that, there's a line that says "Amount billed to card," which is $X +100ish. That was the price the guy gave me over the phone. There's no explanation whatsoever for the difference.

I've booked many hotels with Chase, and this is the first time I've seen this. I called Chase, and after being passed up to a "specialist" (who said she'd never seen this either), and a long time on hold while she called various other people, I was told the difference reflects unspecified "third-party fees." She didn't even seem to understand exactly what that meant.

I'm wondering if I should push back with Chase on this. I'm also planning to call the hotel itself to see if maybe it'll give me a better price for booking directly with them. But I figured I'd ask here first because someone might have had a similar experience.