The post today covers hooking in with the Qt Quick 2 renderer, OpenGL underlays/overlays, and the other steps for integrating this OpenGL code with Qt Quick 2 applications. HOwever, at this time there is no support with the Qt Quick renderer for modifying the OpenGL state.
You can read the lengthy post in full at KDAB.com.
Meanwhile, Mike Krus of KDAB also published today porting Qt 5 to Apple's tvOS. Based upon Qt's iOS port, the Qt5 tool-kit is now being ported to Apple TV.