Lots of different types of love can be found in As You Like It. Some of the love is felt spontaneously and some of it not so spontaneously depending on the character. Oliver and Celia's love certainly is an example of spontaneous love, while Silvius and Phebe's love certainly is not.
When we first meet Silvius in Act 2, Scene 4, we are not told much about the nature of his love for Phebe. Perhaps he spontaneously felt love for her upon first sight; perhaps he didn't. What we do know for sure is that he is in love with the scornful Phebe to the point of distraction, as well as to the point that his feelings torment him. We also know that Phebe does not return his love and, therefore, certainly does not feel spontaneous love for him. Instead, Phebe actually falls for Rosalind disguised as Ganymede quite spontaneously. In fact, Phebe falls in love when Ganymede scolds her for being so vain, selfish, and cruel as to reject Silvius's love. Phebe is apparently so taken by Ganymede's looks that she claims she would rather hear Ganymede scold her than Silvius court her, as we see in her lines:
Sweet youth, I pray you, chide a year together:
I had rather hear you chide than this man woo. (III.v.64-65)
What's more, Rosalind actually must trick Phebe into marrying Silvius to help create the play's happy ending, and the readers and viewers hope that Phebe will grow to love Silvius through their marriage.
Hence, we see that Phebe's love for Silvius certainly is not spontaneous, but hopefully she will grow to love him, showing us that Shakespeare portrays many different kinds of love in As You Like It.