I recall when RTG meant that certian graphics packages (ImageMaster r/t, ADpro, ImageF/X, and others) could ReTarget the image to the early 24bit display cards/framebuffers such as Firecracker24, OpalVision and others, allowing one to actually see all 24bits of color while manipulating the image thus lifting the optical barrier of working on a 24bit image in standard Amiga resolutions.
To answer to OP question:
Yes with the A3000.
No with the VT/Flyer system.
