Same taxonomy in two content type
You can have same taxonomy being used by multiple content types. 

You can achieve this by using 2 options
1. Overriding node.tpl.php for the taxonomy page. Here you can create two separate tpl files specific two different content types.
2. Create PAGE display of VIEWs and pass "type" as an argument. Based on this argument you can always display the teasers belonging only to the desited "Content Type."

Option # 2 is little easier from implementation point of view whereing Option # 1 though could little time consuming but will be better from performance perspective.