Hello Rishi,
Chapter 14 of the Criminal Procedure Code lays down as to who can file complaint in respect of certain offences in IPC. But, there is no restriction in respect of other offences in IPC as to who can file a complaint for registering FIR. Therefore, in respect of these other offences, including an offence under Section 354 IPC, any person knowing about the commission of the offence can file the complaint which can then be registered as FIR.
Further, if the victim is not available to give her statement, it will definitely make the case comparatively weaker.
Generally, bail would be granted in a case under Section 354 IPC, if not immediately, then after some days, except where the offence is of a serious nature or has attracted media glare and public outcry in which situation grant of bail may get delayed.