Nothlit is essentially correct.
You can recharacterize your 2016 contribution from your traditional IRA to your Roth IRA. When you do so, your IRA custodian will also add or subtract any gains or losses associated with your contribution. There is no need to report this contribution or recharacterization on your tax forms. It is unlikely, but you may want to take a look at line 51 and Form 8880 to see if your contribution entitles you to the retirement savings tax credit. You should keep track of your Roth IRA contribution, though, because it becomes important later when you start withdrawing money from it and filling out Form 8606.
You can convert money from your traditional IRA to your Roth IRA in any amount and at any time. Although you can think of it as coming from your 2015 contribution or the earnings thereon, or even an earlier year contribution, the IRS doesn't care - all money coming out of a traditional IRA is treated as a distribution. Note that if you do this conversion, the amount you convert will be subject to ordinary income tax. Although in your case, since your 2015 contribution amount was nondeductible, you will only pay income tax on the percentage of your conversion amount that represents the pre-tax portion of your traditional IRA. Use Form 8606 to figure out the amount of the conversion that is taxable - the result will be on line 15 of that form. If you do this exercise, you will note that you should go back to your 2015 taxes and amend them to file a form 8606 to reflect the fact that your contribution to your traditional IRA in that year was nondeductible.
By the way, Form 8606 is confusing as heck to me. I would strongly recommend reading the instructions very carefully and making sure that the results you get make sense to you and match what you read in plain language at sites like the IRS and Fairmark.