The zip download of Bamboo is bundled with the 32 bits tomcat which works fine for both 32 or 64 bits JVM. Now the issue is when we try to install as a service on windows 64 bits. The service installation will fail because the tomcat binaries are 32 bits. We have this issue documented in the JIRA knowledge base article which involves replacing the binaries.
It will be nice if we just provide different downloads for 32 and 64bits.