While much has been written on the topic of homosexuality, both in Sparta and in other Greek city states, the evidence is often second-hand, open to interpretation and / or quite possibly a reflection of an (ancient) author's bias. There is also much controversy among modern scholars (see Wikipedia for a summary and some examples).
Xenophon makes quite a number of references to homosexuality in Greece, contrasting a Spartan man's appreciation for a boy's character with other Greeks' greater tendency to physical relationships. Further, Xenophon says that the Spartan (semi-mythical) law-giver Lykourgos did not approve of physical homosexual relationships but does not cite any law. D.M.MacDowell, in 'Spartan Law' concludes that
there was no law banning homosexual acts with boys in Sparta. Nevertheless, we can accept that moral relationships between boys and lovers was of greater significance and interest than physical ones,....
After also examining the evidence from Plutarch, MacDowell says that this seems more anecdotal than evidence of any laws, adding
the preferable conclusion is that the Spartans had no law on the subject of homosexual relationships
As men were expected to marry and have children who would grow up to become either (for men) soldiers of the state or (for women) mothers of more soldiers, it seems unlikely that homosexuality was encouraged to extent that it with the Theban sacred band. What was encouraged was close relationships between soldiers for military reasons, but this almost certainly went beyond comradeship at times.
Paul Cartledge states that the Spartans
... did not officially encourage, let alone institutionalize, for military purposes homosexual realtionships between two men of adult fighting age.
Nonetheless, according to Cartledge
The Spartans had a reputation among other Greeks, no doubt exaggerated, for being addicted to buggery.