The next flight is at 09:30, so if there are seats on that one the wait might not be that long.

Also, just a note I routinely leave the lounge 20 mins before departure, so even if the flight is running 20 mins late, that still gives you 10 mins on me , depending on where in the airport the SQ25 arrives and the PER flight departs. If lots of transferring pax they might hold the flight, but even if not, they don't close gates until 10 minutes before departure. They usually wouldn't move you to another flight unless they were certain you wouldn't make the connection.