Bottlenecking ??, no not really , that a8 & a 460 are a good pairing , just don't expect a solid 60fps.
The low base clock on that locked a8 means you'll likely be around the 40fps mark most of the time on current game titles.
If its a system you already own the 460 is a good purchase.
If it isn't then you should be looking at an 860k instead or really the new pentium.