You might say that the city is like nature in this poem. Wordsworth’s poetry often celebrates nature, its quiet and solitude. The city is its polar opposite. However, in this poem, he is clearly in awe of the beauty of the city. However, he is viewing the city at its most nature-like time: in the early morning. There is no mention of the hustle and bustle of city life. The people are still asleep. He even describes the buildings as asleep. He does indicate that this beauty is fleeting. It will be gone when the city gets going.
This city now doth, like a garment, wear,
The beauty of the morning; silent, bear, (4-5).
It does seem odd to say that the city is in tune with nature. But maybe it is. Wordsworth certainly describes the city as he would describe nature in his other poems. In its sleeping state, the city is described as interacting with nature. The sun is shining on it. Industry has not yet begun, so there is no smoke. If the city is sleeping, it is breathing and alive, thus completing the personification that the Romantic poets often attributed to natural phenomena. I think you could say the city is in tune with nature in one respect and it is a stretch. If we say the people of the city, who are asleep, are in tune with nature, it is because they are asleep. They are not being social or industrial and the image of the city in the early morning reflects this. Being asleep, they are dreaming and breathing. These are somewhat like the elements of poetry and imagination that Wordsworth celebrated. His theory of poetry was centered on the individual imagination and that poetry was the spontaneous overflow of emotion reflected in tranquility. What could be a more appropriate way to describe an individual in the process of dreaming.
It is fleeting. And this is the only time when a city dweller (or the city itself) can be nature-like, or “in tune” with nature as you put it. As soon as the people get up and the factories fill the air with noise and smoke, that congestion will obscure any connection or comparison with nature.