As many as you like!  A portfolio is a type of asset in Pebble+ - a presentation of evidence of things you have done or achieved.  This might be in the form of a portfolio, or an activity log, or even a CV created using a Page.  In Pebble+ you can create as many of each of these (and lots of other types of assets) as you want or need.  This means that you can create different eportfolios for different purposes and different audiences.