Last time I went back was only with a one way ticket. As you have a filipina wife, I am sure you wont have problems. If the airline know the rules they will not make a problem. Worst case scenario if they refuse is to book the cheapest flight out on your phone so you can show an eticket, but really, boarding with your wife, explaining you are getting a balikbayan visa (one year) is enough. I have entered many times from China to Philippines with no forward ticket.