Nintendo's GTS doesn't recognize any shiny manaphy as legal, as the only way to get them is via a wondercard method (it's particularly a method 1 pokemon, but undergoes a shiny check just like dynamic wondercard pokemon). It just thinks it is a hack, nobody else will see it.
I heard that shiny celebi has problems in black and white's GTS, if the jirachi does too then it's got a similar shiny check mechanism like the manaphy.
It's for Manaphy, at the least.