I would first check the consulate will accept a bus ticket.
Manila is not the best choice for trying to fob off another mode of transport IF they are asking for flights.
I'm still maintaining that something is being lost here in how the blogger is coming across. I'll have money on it that's it not the consulate that's wanting it but the airline check in desks.
I'm not even sure if you could book a bus ticket 2 or 3 months in advance.
I'm simply saying how the airlines want to operate flying out of Manila. Even with a tourist visa, they don't want to board you with no flight out of Thailand. I've seen it with my own eyes there with people arguing that they don't need a flight out because they can extend that visa for another 30 days. The result was they stand there booking flights online in order to get boarded.
I always thought Manila required a flight out of Thailand before they issued the visa but I guess not when I see people booking flights online in order to get boarded?
Whatever the Thai consulate want in Manila, your issue will be boarding your flight to Thailand. With no onward flight from Thailand, they simply won't board you.