There is no one hotel program that works everywhere, so if you have no idea where you're actually going to use hotels, it's hard to say.

But: Since you say you want a card with no foreign transaction fee, while there's a rumor that SPG may eliminate those (see this thread in the Amex forum), at present, the only hotel cards that don't have a foreign transaction fee are the ones from Chase, and thus the very same ones that you can already transfer Chase UR points to (Marriott, IHG, and Hyatt), plus I think the Citi HHonors Reserve card (which earn two free weekend night certificates, which expire in a year) is the one other 0% forex hotel card.

Here's the dliemma for you: In any city where AirBNB is too expensive, the hotels likely are to be too expensive too. So in those cities you may want to use hotel points. Except you're not likely to have many hotel points if you don't stay in cheap hotels where the hotels are cheap.

There are whole swaths of countries with only Hilton, or only Marriott, or only IHG (of those three), or none of those three at all. so you can't just have points with one hotel program and expect it to help you anywhere in the world. (Just for one example, in Norway anywhere beyond Oslo, the only hotel programs from the USA that help are Club Carlson, Choice, and Best Western. No Hilton, no SPG, no Hyatt, no Marriott.)