Per my compliance check software, the easy answer is that they are considered bundled. You must also check the diagnosis for medical necessity. Are these the only two CPTs? I would think there are additional ones which complicates things even more. :)
If you're billing the color flow (93325) because it was done with 93306 then no, it wouldn't be correct to report it separately as the color flow is included in the description for code 93306.

As was said in the first reply, though, this color flow could be reported as part of another study. Possibly maybe patient also had a transesophageal echo done on this same day where color flow was done with the transesophageal echo. Here, it would be okay to report the color flow separately with a -59 because this was a separate study from the transthoracic echo.

So...without knowing the situation here. It's hard to say if it was appropriate or not.

Jessica CPC, CCC