Looking on the internet deeply has found these results:

tip of the iceberg is the most popular phrase on the web.

bulk of the iceberg 1137,000 results on the web	tip of the iceberg 11,540,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	Good enough reason for the Belgian trade unions to sound the alarm and use their right of petition, but this is only the tip of the iceberg. That guest list, the commissioner's son Seems like serving minors in your bar is just the tip of the iceberg. tip of the iceberg. The police indicate that this is merely the tip of the iceberg. I wonder whether this is the tip of the iceberg. Surely a tip of the iceberg? CTA scholarships are the tip of the iceberg, Ray.

bulk of the iceberg

1137,000 results on the web

tip of the iceberg

11,540,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

Good enough reason for the Belgian trade unions to sound the alarm and use their right of petition, but this is only the tip of the iceberg.
That guest list, the commissioner's son
Seems like serving minors in your bar is just the tip of the iceberg.
tip of the iceberg.
The police indicate that this is merely the tip of the iceberg.
I wonder whether this is the tip of the iceberg.
Surely a tip of the iceberg?
CTA scholarships are the tip of the iceberg, Ray.