Something that may have been overlooked.
On the pit stop mat, Phil handed each team a clue envelope along with the manila envelope, and tells the team they are headed to L.A., and to open the clue and read it, but not aloud. And that they should open the manila envelope when they are told to do so in L.A.
It sounds to me as if they were instructing the teams as to something they did not what the viewer to be aware of until after teams arrive at either the airport in Manila, or somewhere in L.A. whether it's LAX or somewhere else.
It may be teams were told to take the one flight to LAX, or something else. But I suspect the manila envelope contains something they will need to use after they have arrived in LAX.