Not yet, but I know that we are getting close where can claim that btc is the strongest currency. I can feel that we just need to take a few more steps before everyone around the world will use btc instead of usd. It may not be a quick transition but I know we will get there.
Everyone know that bitcoin is still deficient to recognition across the world and for becoming the strongest bticoin should be recognized in the world being a legal currency so in this stage we cannot say that bitcoin is strongest. In a sense bitcoin is strongest respect to their policies regarding decentralization and transparency behavior which the people like so much. It is strongest in this sense that the people are trusting on bitcoin very much. Bitcoin has proved the strongest position through his enhanced value.