I just thought I'd share a link to a post on Derek Holland's Skirmisher Publishing blog, where he discusses some additional spells for the vivimancer class in Theorems & Thaumaturgy.
He lists a lot of spells from the AD&D 2nd edition Wizard's Spell Compendium (also a favourite of mine) which fit in with the vivimancer's themes, including a few spells from the Dark Sun setting -- I find the idea of vivimancers in Dark Sun very interesting! (I've actually been contemplating running a Dark Sun inspired campaign in the future, so will definitely be thinking about including vivimancers in there.)
Derek has also created a set of his own spells, taking the vivimancer in some interesting new directions. I'm especially fond of the 9th level spell living architecture.
EDIT: As Dave pointed out, Derek also has a follow-up post with some more ideas & spells for the vivimancer.