Would a Polarising filter have helped this at all?
Almost certainly. Judging by the angle of the shadows, you must have been at nearly a right angle to the sun, when a polariser is most effective on the sky. In this shot, a polariser would have darkened the sky and removed reflections from the foliage, making the greens greener and the yellow a bit more intense. However, it would also benefit from some clouds in the sky, like Bob's for added interest. If you are sufficiently skilled with photoshop, you may be able to make the sky a deeper blue and make the foliage look a bit better, but a polariser can never be replicated fully in photoshop.
Bob: I really like your shot. Like Syncharmony said, the colours all have their own places in the scene. The yellow at the bottom, the green in the middle and the blue at the top. The clouds are just perfect for a shot like this.