If you have a low or healthy weight they will be visible, but at first they just look a little perky and feel like hard lumps under the areola (and you might only have 1 to begin with). If you have male gynecomastic breasts, the buds probably won't be distinguishable even months after starting HRT. The masseur might be a little worried if she feels the firm lump and might even ask you about breast cancer.
But either way, they soon become REALLY painful to even touch lightly, so you won't want anyone going near them. I physically cringe in terror at the thought of my earlier budding self getting a chest massage.