Spanish press reports claim Real Madrid already have a contract agreement with the Welshman.
But Allen, who was coach with Spurs up until last season, told talkSPORT: "The whole situation with the supposed leaks and rumours is quite incredible, but it's not down to the agents, there's only one man that will make that final decision and that's Daniel Levy.
"He's very shrewd in the way he goes about his business, and if he feels Bale is at his highest value he will try and maximise the situation.
"But I don't think Gareth will go this season, purely because I think it's a similar scenario they had with Luka Modric a couple of years ago.
"For Spurs to go global as a product they need to be in the Champions League every single season.
"Champions League football is where they want to be and without Bale I'm not so sure they can do it.
"But if Daniel thinks it's good business [to sell] and Villas-Boas is in a position to bring in the players he wants that can still push the team on to Champions League qualification, that would be fantastic business."