India was never and will never be a US vassal. Its delusions of grandeur is so high that they already talk about how they "dominate" the Indian ocean. Even when India was extremely poor, needing food handouts from the west, it was still part of NAM and pro-soviet bloc.
India is more likely to publicly challenge US than China. There is a strong likelihood that India will become an enemy of US even earlier than China due to foolish delusions. While China stays in the background quietly taking more power.
India has dreams of being a superpower, so they will never be a vassal to anyone. In fact, they're so self-serving that they'll probably never be particularly useful either. I hear about the Japanese deals to partner with India to build AI infrastructure and high-speed rail, and I already know these are going to be boondoggles because India can't help itself.
That said, India is turning on the US right now, but that's purely a move born out of spite. At the end of the day, there's no meaningful way for India to interact with American interests much less be an enemy in any significant way. On the other hand, until India and China sign a formal territorial agreement, India is always going to be very wary of its northern neighbor. And even if such a treaty were to be signed, how many people think that India will actually stick to its stipulations? These two countries are natural rivals so I can't see any long term friendship between them, so it's all a matter of China getting what it can out of the relationship while it lasts.
Then again, Russia and China are natural rivals too, and yet the two are fast friends right now. Still, I can't see the US pushing India as far as NATO pushed Russia, but who knows how stupid they can get?