Join Date: Oct 2014
Programs: Hilton Diamond, IHG Platinum, Bonvoy Silver, BA, AA, FlyingBlue, IberiaPlus,Wyndham Rewards
Posts: 141
Yes, you can.
Yesterday I was able to do this without any problem. I had a long layover at MIA, having arrived into and slated to later fly out of terminal D (AA terminal), but had no lounge access available to me in terminal D. I exited security from D and used the moving sidewalks on the third floor to work my way around to Terminal J. When I presented my AA boarding card at TSA in terminal J, the agent stated that no AA flights leave out of this terminal and asked if I was here for the lounge. I affirmed that I was there for the lounge, and I was permitted to enter through security without issue. It thus appears that this is common and should not be a point of concern at MIA.
On a related note, I found the LATAM lounge and Avianca lounge to be quite nice. The former having more space, nicer furniture and atmosphere, and better drink selection, with the latter having better food, featuring a couple of hot buffet items. Just about good enough to not make me miss having Centurion Club access...