With an SLR you only get true macro focussing on a lens that has proper macro focussing abilities. Unfortunately in the photogaraphy world, there are a huge number of lenses which claim to have macro ability but are stretching the term far too much.

Strictly speaking, macro means that the lens is capable of producing images on the sensor which are the same size as the actual subject or even bigger, at life size this is described as 1:1 macro. Your Tamron lens is only capable of a maximum 1:3.7 "macro", and that's only at the 200mm zoom setting with the subject no closer than 45cm from the lens. By SLR zoom lens standards, that's actually pretty good, but if you want to go closer and get greater magnification you need to either use a supplementary close-up filter lens or for better optical quality use a set of extension rings. The trade off with close up filter lenses is poor image quality and usually plenty of colour fringing and with extension rings is that if you're using a 2x magnification at 200mm, your f5-ish maximum aperture at 200mm becomes a very dark f10.

The only way to get good macro results is to either use a proper (=expensive) macro lens and excellent lighting, or use extension rings plus a good ring flash unit. However you can improve your macro by investing in a more capable zoom lens with a closer minimum focus distance and a better aperture at the telephoto end of the range. This can be expensive, or you can pick up some very cheap 35mm film SLR lenses. Using an adapter will never allow you to achieve infinity focus on a Canon digital SLR but you can get a close focussing 200mm f3.8 very cheaply. The crop factor of your smaller sensor means it will have the same angle of view as a 310mm lens but the aperture will remain at f3.8. As Canon digital SLR's have the deepest body register (lens to sensor distance) of the current systems then you'll also have the effect of using it on an extension ring. The downside is that you'll have to use the lens in a totally manual mode as no information will be communicated to your camera body. By mounting the lens back to front using a reversing ring you can achieve some really stunning macro magnifications but then you need a tripod, powerful flash and absolutely no wind... There was also a Makinon 80-200mm zoom which sells for next to nothing on auction websites, but it had a macro collar which allowed it to achieve around half size macro (1:2).

Alternatively, if the Fuji still works and does the job just keep it in your camera bag ready for those types of shots. overall, that seems the easiest and best solution unless you really want to get heavily into macro shooting.

I hope that I've helped you, please ask more if there's anything unclear. I've tried to keep a very complicated subject as simple as possible. Please also take a moment to rate my answer.