1. Add parentheses and word boundaries:
2. Add the "ignore case" flag at the start:
See InDesign Help | Find/Change for the GREP possibilities. You can use almost all Search commands in a GREP style, but not the Replace ones. ("Almost" because a GREP style, per definition, is limited to work a single paragraph, and attempting to cross paragraphs will automatically make it fail.)
That is ok also, but Jongware's solution was a bit easier.
copy the grep of Jongware and past it in your paragraph style "ainesosat" in Grep style and above choose your caracter style "make bold".
(see my immage above)
in this way the words change automatically (also while writing them)
Yep, done that. I knew all that, just lazy and lousy with grep strings...