Under normal circumstances, your personal property, including recreational equipment such as bicycles, is covered under the personal property portion of a homeowners or renters insurance policy. The problem is, your bike may not qualify for coverage if you are away from home, and your policy may fall short of protecting your personal property if the losses total more than the policy covers.
If the bike was not at your home when it was stolen, your home insurance may not cover it. For instance, if you took your bicycle along on vacation and it was stolen off the back of your RV, your policy may not extend coverage. Some policies do extend coverage to your personal property regardless of where it is at when it is damaged or stolen, but others do not. The only way to know for sure is to read your policy to find out exactly how the coverage for personal property is worded.
Another problem that may pop up is the question of whether you took reasonable precautions to prevent the theft. If the bicycle was locked up at your home it is probably covered, but if you ran in the store for only a moment, leaving the bike unlocked, the loss could be considered due to your own negligence, in which case it would not be covered.
If the bicycle was stolen as part of a home burglary, it would be covered, with one exception. Most standard home insurance policies only cover personal property up to a percentage of the total value of the policy. If your losses, including the bike, add up to more than your policy covers, then some of your personal property will not be replaced by your insurance. A good way to avoid this scenario is to perform a home inventory and make sure that your personal property protection is high enough to cover everything, even if you have to increase that portion of your policy to do so.
Since home insurance policies differ by state and by company, the only way to know for sure whether your bike's theft is covered is to check the policy. If you are not able to determine whether it was covered in your policy, contact your insurance company or agent and have them check it out for you.