AC tends to vary lounge hours depending on scheduled flight departures. The MNL route hasn't launched yet, and nothing has been published, but it's fairly safe to assume that at least the MLL should be open until 01:15, 01:30 or so (usually ~30 minutes before last scheduled departure). Hard to say just how late they'll keep the SS open if that's the only flight left to go, but it's not like they'll close it at 22:00. Worst case, maybe you have go move from the SS to the MLL at 00:30 or something along those lines.