See image:
https://img.skitch.com/20120111-ti84dtwxcgf49swkmhcqd9q9e.jpg

Comparing same theme in TextMate and ST2. Notice where some items are colored differently. Why is that, and where can this be tweaked?

Are the syntax names the same? (i.e as displayed via control+shift+p)

Here’s what I get for the 3 examples in my screen shot:

COMMENT ST2: punctuation.definition.comment.html.js source.js.embedded.html text.html.basic 
COMMENT TM:  punctuation.definition.comment.html.js comment.block.html.js source.js.embedded.html text.html.basic 

BLOCK JS ST2:  entity.name.tag.script.html source.js.embedded.html text.html.basic 
BLOCK JS TM:   entity.name.tag.script.html source.js.embedded.html text.html.basic

SRC JS ST2: entity.name.tag.html meta.tag.any.html text.html.basic 
SRC JS TM:  entity.name.tag.html meta.tag.any.html text.html.basic

So, the JS < is the same, but a differing color, and the comment is a different syntax