We're flying Melb-Singapore return with QF in Jun and then onto Sth Africa return with Emirates. We've bought 2 QF lounge passes with the original intention of using these before we fly back to Melb on QF. However going we have a 3 hour 15 min layover between the QF flight arriving Singapore and the Emirates flight leaving. Can you use lounge passes at the destination (Singapore) when we get off the QF flight?