Actually, there are more than two main bus terminals. It all depends on your destination/origin. Buses from Singapore stop at either the Puduraya Bus Terminal or the Pasarakyat Bus Terminal. (Bukit Bintang is in between the two terminals.) In your case, Transtar buses stop at the newer and less congested Pasarakyat Bus Terminal, and it's very near Ritz Carlton, probably a 10-minute walking distance. Ask around, the bus driver, or the bus company staff at the terminal for directions. Get a taxi if it's raining or the sun is scorching hot.
There's only one bus terminal at Jalan Pudu, and it's called Puduraya Bus Terminal. Pudu Station is the LRT station in Pudu.
This map will give you a better idea on the locations of Pasarakyat, Ritz Carlton, and Bukit Bintang shopping district. Puduraya Bus Terminal is not shown on the map. It's only about 500m away from the Swiss Garden Hotel at the tip of Jln. Pudu on the map.