Choosing an "alternate build" is 100% fine, but it comes with consequences such as these.
Here is your problem in a nutshell:
(1) Your bio really isnt going to make a difference. Alot of players dont read them. They cant see your bio in the LFM interface or when you apply for an LFM. It isnt visible when standing next to you unless they ID you. If there is something in your bio that you think is important info for others in your group, you should tell them yourself. Its rather like having info on your business card -- in your wallet.
(2) FVS and clerics generally come in two main flavors: Healers and Battleclerics -- with it being generally ore common among FVS. In general, these two playstyles do not mesh -- that is, it is completely possible to do both, but it is not common for a player to actually do so. They generally are either one OR the other. Whether or not this is a fact isnt even relevant -- this is the player perception, ergo it is the only "fact" that matters.
(3) Knowing this, when players see you walk up to the group wearing a bow, the immediately think PEW PEW! and assume your first priority is NOT going to be healing. Remember, they cant SEE your necklace, to know that you have your potency on it. The most common place for healing boosters is on your wpn, followed by your shield. All they see is a FVS wannabe archer. Experience has taught us all that those players suck as healers, because they are focusing on something else.
(4) Your build itself only lends more credence to this assumption. Looking at it, the PL probably assumed you were a BC or an AA, and the bow only confirmed it. I personally would have asked before recruiting you if you could handle the heals, and taken you at your word until proven otherwise. Many players will not.
Expect things like this constantly unless you take a proactive stance on it. Talk to your group. Accept that you are going to have to explain yourself over and over, and prove yourself over and over -- until you build up a good reputation and a 'fanbase' on your server. Prove yourself a good healer and you will get added to friends lists and invited constantly -- whether you want it or not Make your own groups or run with friends and guildies. Mainly though, the key is communication. If you are talking with the rest of the group, they are more apt to ask "dude whats up with the bow" than to just kick you without comment. Thus you get the chance to link your necklace and talk about your build etc. Oh and word to the wise: starting your intro to the group with "dont worry about my bow <link to necklace>" or some such similar comes across as defensive and desperate -- both of which put you on lower ground. Just talk to your grouo. It solves alot, and makes it more fun anyway