Enter each session without knowing when the bonus lands
The 5x3 grid and 20 fixed paylines of The Big Dog House give no fixed schedule for the bonus round. How often free spins arrive is not known in advance, and the result of one session is random, whatever the RTP.
Eight RTP versions of The Big Dog House run from 96.43% to 96.56%. Which version this site runs is shown only in the game rules. Over a long run, the gap between the lowest and highest version is 0.13 percentage points, so the version changes the expected return only slightly.
x15,000 times the bet is the maximum win of The Big Dog House, and it is reached very rarely. At the example top bet of A$5, that ceiling comes to A$75,000. It is a limit on the payout, not a target that any session is built around.