VP and Firelands rep trinkets are total garbage for resto. Well spirit one is some use, but it's still mediocre.
Some T11 trinkets are better.
I did not even bother to use it while we ran FL. But i have been lucky with HC Jaws from HC Domo.
Foul Gift of the Demon Lord is a decent trinket - gives approx +8% mastery when procs. And it does procs quite often.
Nice amount of passive intellect makes it usable in both your specs.
From raids try to get
Windward Heart as your main trinketand
Heart of Unliving as your mana regen trinket.
Alternatively you can persuade your guildies to run Firelands and kill Majordomo on HC mode - with amount of DPS today, he is just as easy as in normal mode+HC neck from him has even more mastery (and the same int) than neck from HC Morchok.
Jaws of Defeat are still viable mana regen trinket, with amount of passive intelect surpassing even HC Heart of Unliving.