The Rebels had harboured hopes of squeezing into the playoffs after the Blues' victory over the Highlanders on Friday but the defeat in Canberra for Kevin Foote's injury-hit side brought a close to a frustrating campaign.
"We've got a platform there now where we know how we want to play, what that looks like and what it takes to win," Wilkin said.
"There's some lessons that we learned this year and what we need to do better to get those wins. It's a learning experience for a lot of guys.
"The group is very strong and we'll keep working towards next year. We'll be a lot better for it."
The loss to the Brumbies, who finished the regular season as Australia's highest-placed team in fourth, was the Rebels' 10th defeat from 14 games.
Only the winless Moana Pasifika, with 13 defeats from 13 going into Saturday's clash with the NSW Waratahs, finished below them in the ladder.
Head coach Foote was unhappy his team had been unable to keep their Super Rugby campaign alive for at least another week.
"It's very disappointing," he said.
"It's not where we set our goals to be. We played some really good rugby this year.
"It's a really nice group to coach and I feel really disappointed that it's come to an end.
"Sometimes you get to these points of the season and the group's a bit drifted or they're not all committed, but I never felt like that with this group."
