Let's be pedantic and state that lounges are not brand standard at St. Regis and W hotels (probably also not at Luxury Collections though I believe more do have them even if they are not obliged to give elites access) so whether elites have access or not to something that doesn't exist is a moot point. In fact, I know of one W that has a lounge and that's in Guangzhou and they do give elites access but it's quite off the beaten track for casual travellers to visit. The OP should also know that Marriott doesn't allow lounges at its resort hotels and closed down the lounges at various SPG resorts (Le Meridiens, Sheratons etc.) when it took over but there's still a few anomalies on that list. While on that subject, nobody's mentioned the Marriott Ocean Park in Hong Kong that designated itself a resort a few years ago so it could exclude elites from its lounge while keeping the lounge open for guests who paid for an executive room. It's a resort in the sense that it's next to a water park and has a swimming pool suitable for kids. How the other Bonvoy hotels - including HK's Courtyards that do have lounges for elites despite not being brand standard and unheard of in the US - must look on jealously.

I'd love to know the know the thoughts going through the OP's mind now about Marriott's inconsistent brands, elite status earning anomalies, variable lounge services, and pretty-consistent-but-not-always lounge access now they've been exposed to the red raw truth. We all seem to muddle through it though.