It depends upon how technically accurate one wants to be.
The CG1123 is the same watch, regardless of whether it's on a bracelet or leather strap. But Senna only wore his with the leather strap. So technically I feel that is the Senna model. Having said that, there's an argument to be made that the bracelet version is too, because one could easily swap the bracelet out for the leather strap.
If one wants to be even more technically accurate (or anal), Senna wore the s25.706c not the CG1123. TAG Heuer changed their ref numbers scheme, so the CG1123 is basically the same watch as the S25.706c, but with a newer reference number. Hence both are called the Senna model. However there's a few small differences. The CG1123 added "Professional" to the dial and the case has a very light brushed finish. The S25.706c only had "200 Meters" and the case finish lacks the light brushing.
Here's a side by side of the two. (Pic courtesy of
@Snowy)