Sri Venkateswara temple at Tirumala follows Vaikhanasa Agama. Can it be considered a Sri Vaishnava temple?
The term Sri-Vaishnava in common parlance refers to followers of Nammazhvar (Sharanagati) and Ramanuja (Savisheshadvaita philosophy). Both in Pancharatra and Vaikhanasa temples throughout India one can find idols of the Azhvars and Ramanuja. Therefore it is reasonable to assume that Vaikhanasas consider themselves followers of Nammazhvar and Ramanuja, hence are Srivaishnavas.
Nevertheless, here is a statement from Mahamahopadhyaya Srivatsankachar in the introduction to Uttamur Swamy's Vaikhanasa Vijaya which makes it clear that he considers Vaikhanasa as Srivaishnava:
śrīvaiṣṇava āgamāḥ dvividhāḥ - pāñcarātram vaikhānansam iti
netradvayamiva āgamavibhāgadvayamapi viśiṣṭādvaitinām
There are two types of "Srivaishnava Agamas" - Pancharatra and Vaikhanasa. For Visistadvaitins these two Agamas are like the two eyes.