Your spirit is really low, which is likely why you're not seeing good results. With heartsong up (it usually is), I have very nearly double your spirit. People using things like http://www.wowhead.com/item=58184 and http://www.wowhead.com/item=59354 and having spirit on every item (I don't, I'm fairly comfortable with ~2500) could have roughly *quadruple* your spirit during MTT.

Hm I don't think any mana tide lasts for only 5 seconds, it's 12 secs by default :P
Did you spec into Totemic Focus? http://www.wowhead.com/spell=16222

Another thing you could do is as mentioned in the article: get a trinket that gives spirit on use, and pop your mana tide right after using it. Currently I am using the JC trinket (Figurine - Dream Owl) and I seem to get about 1/3 of my mana back using those in combat.
Also use your trinket + totem combo early; when you get to that point where it will restore you to nearly full mana. If the fight takes long, you'll then be able to use the trinket and maybe the totem a second time.

http://www.wowhead.com/spell=16222 = 16.8 second mana tide totem + 7 minute totems overall. Must have.

Just tested. No water shield, tide, combat, 2249 spirit(2422 combat regen) pre-tide.
25% mana gained or so.. Totally un-scientific, un-theory-crafted number too.