A major consideration is to make this part of your unofficial research. Finding others who may work there, have experience there and the like is important for all kinds of reasons, not just travel. It doesn't help to learn that the policy allows for F/J TPAC travel, but to later find out that "nobody here does that".

If the job involves occasional short/mid-haul travel, asking about specifics at a first interview shows that you don't have your eye on the big picture.

But, where there is a lot of travel, it is long-haul, or the service standard really matters at the destination, it is important to nail this down. No use in going all the way through the process only to find that the travel policy is unacceptably limiting.

I would not focus on small things, e.g., whether it is Marriott vs. Hyatt and whether you can expense the mini-bar, but asking about important specifics such as the cutoff for F/J and general expectations about on-the-ground are reasonable.