My bread is tasteless

You do not need the fancy equipment of a typical bakery. It helps, but it is not necessary.

What will likely take your bread over the top is some sort of pre-ferment, which I see you've already found in your recipes, but I have a slightly different suggestion than those recipes provide. The simplest way to do this is to make a small amount (perhaps 1/3) of your dough one night in advance. Let it rise once, then retard further proofing in your refrigerator overnight. Before making your full dough, remove it from the fridge and let it warm to room temperature for about an hour. Cut into several pieces. Add to your dough when you add the liquid. The pre-ferment gives your dough something similar to what a bakery with a 9 hour full cycle for making a baguette would have. Your dough should go through an additional proofing plus rising time after shaped. When shaping your dough, be careful to degas it as little as possible.

For a good texture, bake your baguettes on a pizza stone with plenty of corn meal underneath. Pre-heat a thick, ovensafe metal pan with your stone. When you put the bread in, put a cup of boiling water in that pan to add steam. This will help create a great crusty bread crust and oven spring in your dough. I have found that the same baguettes with oven spring taste 100% better than those without - something about that key activity during the first minutes of baking really brings the tastes over the top.

More information on amazing bread can be found in The Bread Baker's Apprentice or, for whole grains, Peter Reinhart's Whole Grain Breads.

ALL the flour needs to soak for at least a day at cool room temperature to fully saturate and start autolysis. Use enough cold water to make the dough stick together, but not to be slippery. Only add the other stuff after a day (salt, yeast, oil etc) and rest of water as per recipe

Edit Under French law a baguette must have 3 to 11 hours of autolysis I find local flour to be not as strong, so use a whole day

Domestic ovens can't get hot enough for this type of bread. To help, remove everything from the oven that you don't need, and just use a thin steel tray to bake the bread on. Preheat the oven for up to 30 minutes with temperature on MAX. It should take no more than 20 minutes to bake, though I am not sure if this will effect taste, but will effect texture. Only use a small amount of hot water to steam the oven

For extra flavour try wholemeal flour as it has more tasty stuff in it, 50% to 100% wholemeal will do. If the wholemeal looks too coarse, give it a few moments in a food processor

Also try different yeast types, and brew your yeast up with tasty flours or other sugars to start it

Another option is to try a percentage of barley flour. Barely doesn't make a great bread, but helps the soaking/sugar breakdown process, and makes the taste more interesting. You can make flour from barley meal with a few minutes in a food processor

You might also want to take a look at Rose Levy-Berenbaum's "Bread Bible". She also advocates for a really long ferment for most breads, and her technique for sponge is pretty awesome.

Filtered water does help make a difference. It's tough to say what is causing the bread to be bland. Letting it sit overnight, usually helps in that department, but also an addition of salt. As you add salt though, you will probably want to add yeast as well, not much mind you, but a little extra of each could be beneficial. You might try changing the type of yeast you are using, or maybe the brand. Same thing with the flour, try a different brand and see if you notice anything. Everything you add or take away will change the texture that you seem to have perfected though, so proceed with caution.

Or you can always do what I do with bland bread: Olive Oil, chopped fresh garlic, a lot of black pepper and a heavy pinch of salt. Nothing better for dipping a nice fresh crusty bit of bread.