I have a
// ... in MyAppDelegate.m
firstViewController.hidesBottomBarWhenPushed = YES;
//... in firstViewController.m
secondViewController = [[SecondViewController alloc] init];
secondViewController.hidesBottomBarWhenPushed = NO;
[[self navigationController] pushViewController:secondViewController animated:YES];
This is what the documentation for
hidesBottomBarWhenPushed says (emphasis added):
If YES, the bottom bar remains hidden until the view controller is popped from the stack.
So it looks like the behavior your're seeing is just what the documentation says will happen. You start by pushing a view controller onto the stack which has
hidesBottomBarWhenPushed = YES. At that point, pushing other view controllers onto the stack won't change the hiddenness of the bottom bar. As long as that first view controller is on the stack, the bottom bar will remain hidden.
So I think you'll have to come up with a different way of accomplishing your UI goal. One option would be to present the first view controller as a modal view controller over the tab bar controller's view. Then, when you want to go to the second view controller just dismiss the first one and viola. The only visual difference will be the transition animation.
There are surely other options too, but that just came first to my mind.