Tonya is an American diminutive of Antonia — from the Latin gens name Antonius ("priceless, praiseworthy") — also influenced by the Russian Tonya (short for Antonina). The story was dramatized in I, Tonya (2017), for which Allison Janney won the Academy Award for Best Supporting Actress and Margot Robbie (as Harding) was nominated for Best Actress. Tonya Mosley — co-host of NPR's Fresh Air. Tonya in Doctor Zhivago is Tonya Gromeko, Zhivago's wife.
Tonya does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Tonya reduce to 3, The Communicator. This is a traditional interpretive system, not a factual claim about the name.