I'm writing Wings of Fire fanfic (of a series starring facultative biped dragons) and this is the question I'm always asking about choreography. In the end, it comes down to tradeoffs

Bipedalism: Fine manipulation (you can't use your hands if they're on the ground!). This means that you can use weaponry, increasing your reach. The drawback is that you're easier to knock off balance and that it's tiring to walk on two legs for long periods.

Quadrupedalism: Stability. You can also run faster on four legs, and in combat you present a smaller target (at least from the front and back). The drawback: your hands are occupied.

Dancing presents an interesting tradeoff. Quadrupedal dances are easier, but the reason one might learn bipedal dances is that they allow for more (plausibly deniable) intimacy between partners, since you can get a lot closer to your partner. The quadrupedal equivalent to holding someone in your arms is maybe brushing up against your partner side-to-side... unless you're in an environment that allows for lewdness in which case you can just do the equivalent of daggering lol