What I found out that I get CL access automatically (as one should) and as a Plat if CL level room (with my bed preference) is available I get it. However not guaranteed. Sometimes only 2Q or 2D rooms are available on CL (I usually have 1K preferred). They would tell me that upon checking (when I ask if there is an upgrade available) and I can make a decision what I would like CL or 1K room or something.
Usually a nice question at check-in helps resolve any issues with upgrade (perceived or real). Usually I find that it is just perceived (not that I have a way of knowing if they are sandbagging me or not
