Ok, so I'm taking it there's only one lounge. On the way out to Heathrow I visited the lounge near gate C33. However, I'm looking at my options for my return to the States tomorrow. My connecting flight after the BA flight is on AA. I know that there is an AA AC in the terminal, but, according to Toronto Pearson's airport website, there is a second BA lounge close to the AC.
http://gtaa.com/local/files/en/Maps_T3.pdf

Does anyone know if this is true? Or has that lounge been moved to where the current lounge sits and the airport's website still hasn't updated?