I just installed a new Hot water heater and have hot water pressure at all faucets but the both the shower/tubs. Very little hot pressuer at all!! WHat can be the problem have bleed intire system. Help!!

You have good hot water pressure everywhere but the tub/shower. Correct?
Here's what I think has happened. In replacing the heater you broke loose some minerals built up in the pipe walls and the first faucet you opened up sucked the crud up into the cartridge where it's now clogging the hot water inlet ports,
The solution would be to turn off the water, open up the valve and remove the cartridge,
Check and clean the inlet poets.
Now turn the water back on for a few seconds to flush more crud out of the supplies. Reassemble and test. Got pressure now? Good luck, Tom