(The following is my attempt to make sense of Rāmānuja’s conceptions of bhakti. Comments and criticisms are welcome!)
To Rāmānuja (traditional dates 1017–1137) are attributed, with more or less certainty, a series of Vedāntic works, namely the Śrī Bhāṣya (henceforth ŚrīBh) commentary on the Brahma Sūtra (henceforth UMS), which is his philosophical opus magnum, both in length and philosophical depth, the Gītabhāṣya on the Bhagavadgītā (henceforth BhG), a compendium of his philosophy, the Vedārthasaṅgraha, and two shorter commentaries on the UMS, namely the Vedāntadīpa and the Vedāntasāra.
Beside these works, the Viśiṣṭādvaita Vedānta school, at least since the time of Sudarśana Sūri and Veṅkaṭanātha (also called Vedānta Deśika, traditional dates 1269–1370), recognised Rāmānuja as the author of also three extremely short works (about 3–4 pages each), namely the Śaraṇāgatigadya, the Śrīraṅgagadya and the Vaikuṇṭhagadya, and of a manual of daily worship called Nityagrantha.
The terms bhakti `devotional love’ and bhakta `devotee’ are not very frequent in the ŚrīBh, where they are mentioned slightly more than ten times, a portion of which in quotes (some of which from the BhG). By contrast, the Śaraṇāgatigadya mentions bhakti 19 times in its only 23 sentences, and adds further elements to it (such as Nārāyaṇa instead of Kṛṣṇa as the object of devotion, and the role of prapatti ‘self-surrender’, see immediately below). Does this mean that the Śaraṇāgatigadya is not by Rāmānuja and represents a further stage in the theological thought of Viśiṣṭādvaita Vedānta? Alternatively, one might suggest that Rāmānuja addressed different audiences in his philosophical and in his religious works. In other words, the difference between the position of the ŚrīBh and that of the Śaraṇāgatigadya could be only due to the fact that the first develops a philosophical discourse about God, whereas the latter enacts the author’s relationship with Him.