Given the response, please synonym:
If you want to have one single tag, use macintosh.
If you want to split the questions into two groups, there are several ways Macs can be divided. For example:
PowerMac, PowerBook, iBook, Cube, iMac (some)
Mac Pro, mini, Xserve, MacBook, MacBook Pro, iMac (some)
And of course, there are bound to be questions about Linux on devices that ship with iOS (iPhone, iPad, Apple TV), so you might want to keep those in mind, too.
PowerPC is an architecture like x86 or x86_64. Modern Mac's run on Intel and are not PowerPC. Also PowerPC was an IBM architecture, and I don't think apple was the only hardware that had it (I might be wrong). So
/macbook should not be a synonym of
/macintosh and neither should
/powerpc. As far as
/macbookpro they are probably completely unnecessary, I would think the underlying architecture to be more interesting, this is like tagging
/inspiron I really doubt those last 2 tags are remotely relevant