Spurs coach Andre Villas-Boas fears that Bale could leave the club if they fail to qualify for the Champions League at the end of the season.
Vertonghen showered Bale with praise, telling TalkSport: "I'm glad he's a part of our team.
"I'm pleased I don't have to play against him, except when I represent Belgium!
"He's an amazing player, everybody can see that. I hope he stays next season as well."