org-list-two-spaces-after-bullet-regexp

org-list-two-spaces-after-bullet-regexp is a variable defined in `org-list.el'.
Its value is

nil

Documentation:
A regular expression matching bullets that should have 2 spaces after them.
When nil, no bullet will have two spaces after them. When
a string, it will be used as a regular expression. When the
bullet type of a list is changed, the new bullet type will be
matched against this regexp. If it matches, there will be two
spaces instead of one after the bullet in each item of the list.

You can customize this variable.