I understand that the layout shown is nowhere near finished, but thought I'd mention that there are a couple of things about it that need to be adjusted. Let's refer back to the schematic in your first post. The network in that schematic, consisting of C12, L13, C13, L14, and C14 does not appear to be a matching network because the values are symmetrical. I think that this may be a low pass filter. I also note that the TI reference design has all of the connections starting from the top of C12 as 50 ohm microstrip lines. That supports my belief that this is a low pass filter since we would not normally force the use of 50 ohm tx line in a matching network unless it was necessary. I think all of the impedance matching to get to 50 ohms is done by the balanced to single ended conversion network consisting of L11, C11, L21, L12 and C22. In your layout, you do not leave enough room to implement a good 50 ohm line in your connections of your C15, L6, C16, L7, C17 and up to L8. So you will have to spread those out a little bit depending on your dielectric thickness. Also, you show C15 as a stub off of L6. You should change so that the 50 ohm line passes directly through the hot side pad of C15 so that only the capacitor is stubbed, not the trace up to the capacitor.
In your layout, L8, R2 and L9 are meant for impedance matching the antenna to the 50 ohm line, but they are optional and so if you do not populate L8 or L9 and just have a zero ohm resistor at R2 then it would be best if the 50 ohm trace interconnects these parts too.
It is inevitable that your antenna will not be perfectly impedance matched to the transceiver. It is hard to do the impedance matching at 433 MHz without a network analyzer or some such impedance measuring instrument. So you may never know what your impedance is, exactly. This may have only a relatively minor affect on performance unless you are unlucky.
If I were designing this board, I would put the pads down for a coaxial connector at C18, in such a way that soldering C18 down in one direction makes connection to the coax connector and soldering down at right angles makes connection instead to the antenna. This is a handy way of allowing you to test your transceiver with an external antenna or instrument connection. This idea is implemented on the TI reference design.