neutral and transparency are often considered the same by some hobbyists.
in fact they are not.
I have not found many people who believe that. In fact as Jamscience mentioned, one is not event he subset of the other. From the Stereophile Glossary:
neutral - Free from coloration.
transparency, transparent - 1) A quality of sound reproduction that gives the impression of listening through the system to the original sounds, rather than to a pair of loudspeakers. 2) Freedom from veiling, texturing, or any other quality, which tends to obscure the signal. A quality of crystalline clarity.
In my opinion and somewhat based on the above definition, "neutral" is a term that mainly applies to the frequency response of a component, i.e. there are no colorations over the proposed range of the component. Bass extension does not play a role in my opinion though, e.g. many Monitor speakers are considered neutral in their respective range.
"Transparent" on the other hand does not necessarily only make a statement about frequency response, but also affects attributes like timing, rise times, ringing, and most importantly in agreement with part 1) of the Stereophile definition, spatial clues and information.
At the end of the day, it would be nice to have an agreed on Glossary. The main problem here is though semantics: Using subjective, metaphorical terms to gain an objective description is bound to fail.
My 2c,
Rene