WELLL I went and turned off all the layers so I could only see the "bump map layer" for the smaller domes, and... immediately saw my problem. Something had gone wonky when I used the gradient tool, and I just redid that layer.

So then I tried the domes again, repeating the whole bump map process, but this time I took screenshots... for future reference or in case of future problems.

Basic shades-of-grey for bump map:

screen 1.jpg

Setting bump map:

screen 2.jpg

With bump applied:

screen 3.jpg


So... much better now, though still not 100% happy with it, but I think it will look better with my small roof >.< (And Idk why it's so much darker?????)