I'm not sure Spurs will offer many more than the minimum requirement of 3,000 for away fans. They will only be able to sell all of the stadium on a limited amount of games then 60k tickets on others. I think it is an agreement with the local council and residents that they can only hold a certain amount of "Full Capacity" games at Wembley Stadium
Nope the agreement is now 90,000 IF they go ahead with it next season