The Wales international, who is yet to finalise his world-record £86m move to the Spanish capital, is said to be "furious" with Spurs over their handling of the deal.
"I think it will happen but I cannot make any firm promises," Tapias told Marca
"We're going to wait because they are dragging their feet. There are a few problems but I hope they will soon be resolved.
"We thought that he would be with us now but as of the moment, he is not a Real Madrid player although it looks likely that he will join us."
The La Liga giants are reportedly on the verge of dismantling the stage at the Santiago Bernabeu, which had been intended to be the platform for which Bale would be presented to supporters.