Random results and timing of the bonus
Choosing your bet on Sweet Bonanza 1000 comes before any spin, and it cannot tell you when the bonus round will arrive. How often the bonus round comes is not known in advance. The result of one session is random, whatever RTP version applies, so the RTP figure does not promise a win in any single session.
Checking the RTP before you spin means looking at the game rules, because the version this lobby runs is shown only there. The rules name the RTP version in use, so read that line before you set your bet and decide how long to play.
Chasing the top prize on Sweet Bonanza 1000 means chasing a ceiling of x25,000 on your stake, a level reached very rarely. Keep that in mind when you size your bet, since every win scales with the stake you place.