To make messages localization available server-side you need to use ChatComponentTranslation instead of ChatComponentText. I've done this for some files but I don't really know how to use string.format properly.
What files needs to be changed:
TEAltar.java "LP" and "LP/t" should be moved to .lang file.
SigilDivination.java (Lines: 85, 100, 114)
ItemTankSegmenter.java (Lines: 218, 281)
ItemAttunedCrystal.java (Lines: 255, 382)
RoutingFocus.java (Line 118)
ItemRitualDiviner.java ( Lines: 184, 415)
SigilFluid.java (Line 165, also modes should be moved into .lang file)
I hope you @WayofTime or you @Arcaratus can do this.

Will this be fixed for 1.7.10?

No. 1.7.10 is done.

But just so you know, I am keeping this in mind for 1.8:

<TehNut> Also, jsyk, if you use this to localize, it'll allow lang files to set colors/formatting
<TehNut> https://github.com/WayofTime/BloodMagic/blob/1.8-Rewrite/src/main/java/WayofTime/bloodmagic/util/helper/TextHelper.java#L14
<TehNut> Like here https://github.com/WayofTime/BloodMagic/blob/1.8-Rewrite/src/main/resources/assets/bloodmagic/lang/en_US.lang#L81
<TehNut> Returns http://i.imgur.com/4PtDsth.png
<WayofTime> Aye
<TehNut> A bit nicer to translators than hardcoding all the tooltips :p
<WayofTime> Bah :P

This is done in 1.8.

Will do