Terry headed the fourth goal in a 4-0 win as Chelsea reached the fifth round of the FA Cup.
A report claimed Terry and Benitez clashed earlier this month, but the captain branded it "rubbish" and said the two were on good terms.
"It was good to get on the scoresheet and good to be back," he told ITV.
"The manager knows me and I want to play. I have been out for two or three months (with a knee injury), but the other two (centre-backs) have been doing well.
"It's good to have competition."
Terry admitted that Chelsea found it tough to break down Brentford, with all four goals coming in the second half.
"They made it very difficult," he added. "(They had) two banks of four and sat very deep."
Benitez backed up Terry's claim that their relationship was good.
"Clearly you can see, he's on the pitch, he's training," he said.
The Blues have now won three matches in a row and Benitez wants to keep the run going.
"In football you have to win games, in a top side it's even more important," he said.
"I said before this is a team in transition, little by little we will see if we can improve."
Brentford boss Uwe Rosler felt the final score was harsh on his side.
"I think we did very well, I think we made their life very difficult," he said.
"It's disappointing that they scored (the first goal through Juan Mara) from a long kick (and) a shot from outside the box.
"(It was a) little disappointing the scoreline in the end was four, not really reflecting (the game)."