Have Matreiya ever meet the present buddha? I know that the Buddha went to tusita heaven or tavatimsa heaven to teach the dharma or Abidhamma to his mother. Matreiya is in tusita heaven so did he ever come down to tavatimsa heaven to hear the dharma from the Buddha?
Gauthama Buddha first met Mithrie Bodisatta on His return to Sankassapura(Sankissa Basantapura in India) after preaching Abhidhamma at Tavatimsa heaven. At that time, Maithrie Bodhisattva was born as the son of Siriwaddana Situ of Sankassapura.  After listening to a Dhamma discussion attended by Ven. Sariputta, he had expressed the willingness to join the monastic order. Maithrie Bodhisattva obtained the higher ordination from the Buddha himself and was named “Bhikkhu Arya Miethirya.” There after he practised the teachings well and became famous as an excellent Dhamma expounder.

Once Ven. Maha Prajapathi Gotami Theri offered two robes to Ven. Arya Maithriya. Ven. Arya Maithriya offered them back to the Buddha. At that time the Buddha looked into the future and predicted that there will be a kingdom known as "Kethumathi" and a universal monarch called Sankha whose advisor Subrahamme and his wife Brahamawathi will be parents of future Buddha Maitriya and that he will attain enlightenment under the Naa(Mesua Ferrea) Tree. This was the last affirmation received by the Maithriya Bodhisatta. The prediction of emergence of the future Buddha was announced on an Il Full Poya Poya Day. 

There is also a story on Maithriya Bodhisatta meeting Gautama Bodhisatta in the distance past which I'm not including in the answer.