If you make unallowable contributions to a Roth IRA, you need to report that and pay penalties. This is why Turbotax asks about any Roth contributions, to make sure you are eligible. But there is no general rule that you need to report Roth contributions and there is no place on the form to report them. (Form 8606 is used to report after-tax contributions to a traditional (pre-tax) IRA. Even though Roth contributions are also after-tax, a Roth IRA is a different kind of account and contributions are not reported on the tax return unless they are excess and subject to a penalty.)
