What grease have you been using??
The problem with Redline is compatibility. It can be really tough to flush out all the old grease - especially on anything with a boot. If you don't do a perfect job, you are looking at premature failure. After you start using RL, you will have to stick with it for the life of the components or try another flush.
You should look at using two different greases for bearings and suspension. The qualities that make a great suspension grease can be undesirably in wheel bearings. Besides a second can of grease doesn't cost much or take up much self space.
I am not a big Amsoil fan, but I really like their polymeric truck grease for suspension. M1 is a favorite around here, but it has a very thin base. Schaeffer 238 is amazing stuff but completely unsuitable for wheel bearings.