As others have mentioned, getting all the perks of Elite status generally requires BIS. There are some enhancements that can be obtained with $.

American Airlines and Alaska Airlines allow their members to buy upgrades (both in 500 mile increments, I believe). I have used the Alaska Airlines program before to upgrade at the airport, on the day of the flight, from SEA-SFO and SEA-PVR. Alaska does fly trans-Con (JFK-SEA and then SEA-LAX), although I don't know if it flies JFK-LAX. You don't know until you get to the airport, though, whether or not an upgrade is available. I don't know how easy it is to use AA upgrades, but they're only good for travel in North America, the Caribbean, Mexico and Central America. Also, for non-elite AA members, the upgrades are only from Y and B classes.

If you have to fly to India (or Asia) again and you have some flexibility about choice of airline, you could also look into flying an airline that offers Premium Economy, at least to get you across the Pacific, and then connect to a flight to get you to India. For example, Thai Airways would get you to Bangkok and from there I think you can take a direct flight on Cathay (in Economy) to some cities in India. Another airline with PE to Asia is Eva. PE is a fair bit more comfortable than Y. Or you could fly the much longer route and fly PE from the US to the UK and then from the UK to India on British Airways. (PE flights are also tier-point earning flights with BA that will qualify you for membership in Executive Club and get you started on earning status and miles with BA.)