Bhaktamrutha.

Hanumān became great because he was Rāma's bhakta.

And Rāma's greatness became visible to the world through Hanumān's bhakti.

I would slightly refine “Rāma's greatness is because of Hanumān,” because philosophically Rāma does not derive His greatness from Hanumān. Rather, Hanumān revealed Rāma's greatness to the world through his own perfect devotion and service.

A beautiful concluding passage could be:

Writing

The Strange Paradox of Rāma and Hanumān

There is a beautiful paradox in the story of Rāma and Hanumān.

Rāma made Hanumān great.

And Hanumān made the greatness of Rāma visible.

Hanumān had no kingdom.

He sought no throne.

He asked for no reward.

He did not build his greatness around himself.

He became known because he was known as Rāma-bhakta.

The world remembers Hanumān because he belonged completely to Rāma.

And through Hanumān, we come to see another dimension of Rāma.

Who else could inspire such absolute devotion?

Who could make the strongest of beings willingly call himself dāsa?

Who could make a being capable of crossing oceans, lifting mountains and defeating armies say, in essence:

“All this strength is Yours. I am only Your servant.”

Hanumān's greatness therefore becomes a testimony to Rāma's greatness.

And Rāma's greatness shines through Hanumān's devotion.

This is the beauty of bhakta–Bhagavān sambandha.

The Lord reveals His glory through His devotee, while the devotee's glory comes from his relationship with the Lord.

That is why Hanumān's most powerful name is not Mahāvīra.

Not Mahābala.

Not Vajrāṅga.

Not Sankatamocana.

It is simply:

Rāmadāsa — the servant of Rāma.

And perhaps that is the greatest lesson of all.

Hanumān did not become immortal by making himself great.

He became immortal by making Rāma the centre of his life.

He is remembered not merely because he was powerful.

He is remembered because he was Rāma's bhakta.

And through the ages, when we say:

“Jai Hanumān!”

we are, in a sense, also proclaiming:

“Jai Śrī Rāma!”

For Hanumān's glory and Rāma's glory are beautifully intertwined.

The servant points to the Master.

The bhakta points to Bhagavān.

Hanumān points to Rāma.

And perhaps that is the highest achievement of a devotee:

To become so completely His that, when the world remembers you, it remembers Him.