How often will the bonus round appear?
Each spin on the reels lands its symbols at random, so the bonus round might come on the first spin or stay away for a long stretch. Nobody can name how often it will appear before play starts. The RTP is an average taken over a very large number of rounds, and one session can end above or below its starting balance whatever version runs.
Every round on the reels runs under one RTP version of the game, and only the game rules say which one. Read the game rules before you start, because that is where the version is named.
Large combinations on the reels can climb far up the paytable, yet the maximum win is a ceiling reached very rarely. Treat it as the upper limit of the design, not as a number to aim for. Nothing on the reels tells you in advance when a round will get close to it.