Chicago-Milwaukee metro area?

I've been looking at the map and stuff, and the metra lines. But anyway, I noticed that Kenosha is considered to be in the Chicago metropolitan area and sometimes the Milwaukee metro area, I looked on a map and saw that the suburbs all the way to Kenosha are basically connected and then at Kenosha it's Somers, Elmwood Park and Sturtevant, Racine, Caledonia, Oak Creek, South Milwaukee, and then Milwaukee's suburbs start. My question is do you think we should say Chicago-Milwaukee metro area or no? Like we say San Fransisco-Oakland or San Diego-Tijuana etc.