That’s a fascinating thing to consider!  Because the Boonta Eve Classic’s podrace was pretty famous throughout the galaxy–it wasn’t the biggest thing ever, but it certainly had a lot of people’s attention!

The simpler times of peace in the Republic allowed
for leisure activities to achieve galactic attention. The Boonta Eve
Podrace, though based beyond the Republic’s borders in the independent
Outer Rim, garnered coverage and attention even in the Core Worlds.

The government artwork of this time was largely about
preserving the status quo. Peace was good for commerce; as such, the art
beautified the distractions that member worlds offered in the name of
lucrative tourism. Worlds with rich cultures, like Naboo, broadcast
their histories to neighboring planets. Even far-flung worlds with shady
reputations like Tatooine tried cleaning up their image to attract
visitors for such events as the Boonta Eve Classic. During the
Chancellery of Finis Valorum, initial work began on millennial
celebrations that would have marked the thousand-year anniversary of the
Republic’s foundation. Such exploration of logo designs and artwork now
stand as an ironic artifact of a myopic regime, since the Republic
dissolved before any such milestone could be reached.
With eyes toward expansion into the uncharted reaches
of the Outer Rim, the traditions of the Core became passé. Opportunity
beckoned from beyond the borders of the Mid Rim worlds. The congested
planets of the interior were saturated with messages of promise lying
outward, a reversal from long-held notions that Coruscant represented
the icon of advancement. Republic wordsmiths and artists collaborated to
create a sense of civic duty, of manifest destiny, and of deep
obligation to spread the Republic banner from Rim to Rim.

For the well-settled and wealthy elite of the galaxy’s
most crowded centers, such notions were quaint but uninspiring. It was
the citizens of the Inner Rim, those who had been crowded out of
opportunity in the Core, who answered the call for new life in the
frontier of the Outer Rim. 
      –Star Wars Propaganda

We see Anakin has a poster of the podrace in his room, the one that was billed as Ben Quadinaros vs Sebulba that he won as a kid, so there’s certainly a fair amount of popularity in the sport at the time. (ETA:  Upon further poking at the materials, this may not be from the podrace Anakin won as a kid, as Ben Quadinaros continued to race for another 10 years after his appearance in The Phantom Menace and his “rivalry” with Sebulba was played up afterwards.)

We know from Master & Apprentice that Jedi likely often watched podraces, too, so it’s pretty common in the GFFA:

But it was an obsession not unlike those of other
Padawans [Qui-Gon’s] age—who would review lightsaber holos for hours on end, or
follow their favorite racer pilots and boast in any victories. Qui-Gon
never spoke of it, not out of any sense of shame or wrongdoing, only
because Rael had suggested Master Dooku’s opinions about the prophecies
and mystics were complicated.
     –Master and Apprentice

We don’t know how popular podracing still was by the time Luke was growing up, if people still talked about a race from 30+ years ago, or if the Hutts covered it up because they didn’t want it known that a human (a human slave at that, especially one who won his freedom through it) could win the race, but it wouldn’t be impossible!

Owen, Beru, and Luke also live fairly far away from Mos Espa, where the podrace took place (I think it’s something like 300km/180 miles away), as well as it happened quite some time ago, so it wouldn’t have been too hard to keep that info from Luke if they were careful or if the Hutts covered it up, but it would be interesting if Luke ever went to Mos Espa (though, that’s doubtful, the Larses went to Anchorhead to get their supplies, they probably knew to stay away from Mos Espa if they didn’t want to tell Luke about Anakin), but it would be an absolutely fascinating thing to explore, just how much cultural impact a human winning the race like that would have, if Anakin’s name was known on Tatooine after that or if it was covered up because nobody wanted anyone else getting any big ideas.

I mean, Anakin’s poster doesn’t even have himself on it, it’s Sebulba and 

Ben Quadinaros, it seems reasonable that there wasn’t a post-podrace poster for him to get hold of instead, that would have had his face on it.