In this poem (Amoretti Sonnet XXXIV) Spenser is writing about unrequited love. In the poem, the speaker says that he can only wander around, burdened by his cares, sad and comfortless because the woman he loves does not return his love.
In "In Summertime on Bredon Hill," A. E. Housman is also writing about a love that brings more sadness than it does joy. In that way, the love felt by Housman's speaker is similar to that felt by Spenser's speaker. However, the circumstances are much different. Housman's speaker's love is not unrequited, exactly. The object of his love did love him, but she is dead.
In both poems, the speakers are saddened because of the love they feel for others -- that is what is similar. However, Spenser's speaker's love is unrequited because its object does not love him. Housman's speaker's love cannot be reciprocated because its object is dead.