Problem is Xath, your build does not qualify for the class.
the Lore abillity of the Loremaster while functionaly equivalent to the Bardic Knowledge ability is still not Bardic Knowledge.
Going from memory here isnt the only way to learn to speak Druidic is to take a Druid level. I know Druidic is not able to be learned as a bonuses language selection. I'm not sure it is an option to learn by spending a skill point on Speak Language, though I could see a pretty good arguement re: having the Loremasters bonus language class ability be able to select Druidic.
I sorta see what you are going for here, a Mystic Theurge PrC that gives bigger HD, better saves and more skill points. Thematicaly it is kinda all over the board. With Wiz and Cloistered Cleric levels the extra BAB is completely unneccesary, you will not be melee-ing, and your total BAB score will be behind anyway.
The oath relaxing aspect of the class is completely wasted, as ASF will apply to the wizard side, and Cloistered Clerics are not proficient with armor if memory serves correctly. You also get no value out of the increase to Bardic music the PrC grants.
I would instead of Closistered cleric take a level in UA Divine Bard instead, this way your build is more into the spirit of the class, and you get some advantage from the increase of Bardic Music. You are still going to have ASF from the Wizard casting levels.