Relation between interval temporal logic and linear temporal logic
The question you ask is more complex than it seems. ITLs have been defined in different ways and fashions, and the answer depends on the particular definition and the particular semantics. To get an intuition, you have to decide first if points are to be considered special intervals or excluded by the semantics; the second choice is more common, and it makes more difficult the comparison. I suggest to check, first, the webpages 

1.http://perseo.dif.um.es/~guido/publications.html

2.https://itl.dimi.uniud.it/

to get an idea of the last 10 years of research on this topic. Second, you can contact me to discuss more in particular your question (my address is on the link number 1).

cheers