There’s no way to change the font for just the bullets, but you can change the font for the whole heading without changing the default font. Put your cursor on the heading and type
C-u C-x =. This runs
what-cursor-position, which gives you all the details about the character under the cursor. Scroll down to the text properties until you find the “face” being used for this text. It will likely be
org-level-1, unless you were on a heading at a different level. Click on the face name (or move your cursor to it and hit enter), and it will take you to a description of the face and its attributes. You can use the customize button in this view to edit the face; changing the “Family” attribute will allow you to select a different font. You can also change the height, weight, color, and so on if you like.
It’s a little bit annoying that there are eight of these faces, and that they don’t inherit from a useful common face. If you want to use the same font for all of them, you’ll probably want to customize them all.