"We're in good form and confidence is high so hopefully we can continue to make ground on the clubs above us," Johnson said after the game at Ashton Gate on Saturday.
"Back-to-back home matches is an ideal opportunity to do that and we will be looking for three more points on Tuesday.
"I knew this would be a game in which we needed to show patience because Barnsley were always going to get men behind the ball. They also have players who can break on you so it's dangerous to over-commit.
"We kept our composure and eventually scored two superbly taken goals.
"By the closing stages we were dominating and everyone was looking comfortable on the ball."