Before your first spin on Bigger Barn House Bonanza
The 96.50 RTP of Bigger Barn House Bonanza describes what a large number of spins returns over time, not what one session returns. How often the Free Spins or the Wheel Bonus land is not known before you play, and a high volatility slot can run long stretches without either. Every spin is random, so your session result is unknown whatever the RTP says.
96.50 is the RTP printed for Bigger Barn House Bonanza, but a different version of the series can carry its own figure. Which RTP version runs on this lobby is shown only in the game rules, so read them before you start. Better Barn House Bonanza is a separate release of the series with a higher maximum win.
x25,000 is the highest prize Bigger Barn House Bonanza can pay, measured against the bet. The ceiling is reached very rarely, so it is a limit on the top prize, not a figure to expect. At the highest bet of A$240, the same multiple would be A$6,000,000.