Bostock's attitude was questioned by Redknapp after Brentford decided not to extend his loan.
"He wasn't in the team, he was on the bench on Saturday and the Saturday before," said the Spurs manager of the 18-year-old signed from Crystal Palace in 2008.
"When they go on loan they have to get in the team. If they're not playing well enough then they don't play.
"Ankle-deep mud and he was fantastic. It didn't bother him, he adjusted. You have to adjust.
"You're looking for them to make a real impact. And when you get them back you think - stick him in the team."