For sure. I lived in Brazil for 24 years, Tom Jobim is very popular.
Maybe some young people don't recognize or have never heard the poems and songs, but if you were born before 1990 for sure you know him.
His songs played in many national TV shows called novelas..so is very popular.
By name yes, but many of his songs were recorded in the voice of other singers, sometimes they may know the music but not the authorship, another fact is that Bossa Nova is not so popular nowadays, from north to south the musical taste has always been for more danceable music
yes, maybe some young uncultured had never heard his music but the vast majority does