I’ve taken the cAP out of the picture initially, I was trying to get the VLANs working before trying the trunk port and cAP. I have initially followed this config from the pages mentioned up top of this thread - Using RouterOS to VLAN your network
The intention was to get the VLAN's working on wireless interfaces and to provide a MGT VLAN before I tried to convert ether1 to a trunk port and introduce the cAP with VLAN's 10 and 99. In the config example posted above I had tried to put ether1 on VLAN 99 and an access port to see if I could get DHCP working on ethernet vs wireless.