Known rules before the spin, unknown results after
Deciding to start a session means accepting that the bonus round may or may not appear. How often the Free Spins come is not known in advance, and no page can say it for you. The result of one session is random, and that holds whatever the RTP is. The RTP describes the long run, not the next few spins.
Before you bet, check which RTP version Playtime Casino runs for this game. That version appears only in the game rules, so read them before the first spin. The table on this page shows the versions side by side, but the rules name the one in use.
Aiming for the top prize means knowing the ceiling first. The maximum win is x2,100 the stake, which comes to A$525,000 at the highest bet of A$250. That ceiling is reached very rarely, and no session can promise it.