I never had to use my full OMG heals on my bear tank, even in heroics. I usually did regrowth, rejuv, LB, LB, wild growth, drop a hot on another toon to top off from random aggro, rinse, repeat. The tank was usually the least of my worries.

Everyone's experience is different, though. You can surely mix and match things depending on where your spec points/glyphs are.