Supply a custom label via the plan it self. That's the translated and substitution supported plan name. You can use a language string for the plan name and add any HTML, etc.. that you want. Example as follows.
Code:
'PLAN_NAME_1' => '<strong>HTML!</strong>'
Your alternative is in your template file to use PHP to modify it to whatever you want. $this->_labelledName is the plan name with <label applied. While $htmlNameTranslated should be just the plan name otherwise you can probably use $this->_model->getPersonalized( 'name', $user_id, true ).