the only solution I've found so far is to create a point feature class and publish it to AGO - then you can add it to your web map like any other layer
this isn't a great solution for a web map, tho, since the points would be static - you'd lose scalability in the web map unless you created a ton of points and gave them all different scale dependencies. Of course, that also depends on the scale of your other features as well as how many there are, etc.
