"(a) No "Wrapping." You must not create or offer a "wrapper" for the Service, unless you obtain Google's written consent to do so. For example, you are not permitted to: ... (ii) create a Maps API Implementation that reimplements or duplicates Google Maps/Google Earth. For clarity, you are not "re-implementing or duplicating" Google Maps/Google Earth if your Maps API Implementation provides substantial additional features or content beyond Google Maps/Google Earth, and those additional features or content constitute the primary defining characteristic of your Maps API Implementation."
No, this applies to client-side libraries. OpenLayers required a specific letter from Google saying the terms didn't apply to them (but will apply to others).
https://developers.google.com/maps/terms 10.2(a):
"(a) No "Wrapping." You must not create or offer a "wrapper" for the Service, unless you obtain Google's written consent to do so. For example, you are not permitted to: ... (ii) create a Maps API Implementation that reimplements or duplicates Google Maps/Google Earth. For clarity, you are not "re-implementing or duplicating" Google Maps/Google Earth if your Maps API Implementation provides substantial additional features or content beyond Google Maps/Google Earth, and those additional features or content constitute the primary defining characteristic of your Maps API Implementation."